EP0679974A2 — Integrated vehicle positioning and navigation sys…

Claim 1

Independent Claim 165 words

A computer-based system for autonomously navigating a vehicle (102) along a predetermined path, the system comprising: first means (1000) for determining a location of the vehicle (102), the first means including: a first positioning system (700) adapted to provide a first position estimate (716) of the vehicle (102) based on first signals (110) from a terrestrial position determinating system (200-206, 624); a second positioning system (900) adapted to provide a second position estimate (908, 910) of the vehicle (102) based on second signals (908, 910) obtained from an inertial reference unit (904) mounted on the vehicle (102) and a vehicle odometer (902); and a processing system (1002, 1004, 1020) adapted to compute a third position estimate of the vehicle (102) from the first position estimate (716) and the second position estimate (908, 910); second means (5306) for causing the vehicle (102) to track the predetermined path; and third means (4150) for causing the vehicle (102) to detect and avoid obstacles while tracking the predetermined path.

Claim 2

Dependent Claim 66 words

A system according to claim 1, wherein the terrestrial position determinating system (200-206, 624) has at least one source for transmitting the first signals (110), the at least one source comprised of any one of one or more pseudolites (624), a global positioning system (200-206) having at least one orbiting satellite (200-206), and both the global positioning system (200-206) and the one or more pseudolites (624).

Claim 3

Dependent Claim 107 words

A system according to claim 1, wherein the processing system (1002, 1004, 1020) comprises: an I/O processor (1002) coupled to the first positioning system (700) and the second positioning system (900), the I/O processor (1002) adapted to receive the first position estimate (716) and the second position estimate (908, 910) respectively; a main processor (1004) coupled to the I/O processor (1002), the main processor (1004) for computing the third position estimate from the first position estimate (716) and the second position estimate (908, 910); and a communications interface processor (1020) coupled to the main processor (1004), the communications interface processor (1020) for distributing the third position estimate.

Claim 4

Dependent Claim 55 words

A system according to claim 2, wherein the first positioning system (700) further comprises a reference receiver (316) at a known location situated near the vehicle (102), the reference receiver (316) for receiving the first signals (110) from the terrestrial position determinating system (200-206, 624), and the reference receiver (316) for computing a differential bias.

Claim 5

Dependent Claim 131 words

A system according to claim 2, wherein the first positioning system (700) comprises: an antenna (702) for receiving the first signals (110); a preamplifier (704) coupled to the antenna (702), the preamplifier (704) for amplifying the first signals (110); a first receiver (706) coupled to the preamplifier, the first receiver (706) for tracking the sources (200-206, 624) currently observed and for deriving actual pseudoranges (R₀, R₂, R₄, R₆) of the sources (200-206, 624); an intercommunications processor (708) coupled to the first receiver (706), the intercommunications processor (708) for receiving the actual pseudoranges from the first receiver (706) and distributing the actual pseudoranges and status information; and a GPS processor (710) coupled to the intercommunications processor (708), the GPS processor (710) for computing the first position estimate (716) from the actual pseudoranges.

Claim 6

Dependent Claim 28 words

A system according to claim 3, wherein the main processor (1004) comprises software including a second Kalman filter (1202) for filtering data from the inertial reference unit (904).

Claim 7

Dependent Claim 34 words

A system according to claim 4, wherein the differential bias comprises an original bias computed by subtracting estimated pseudoranges (R₀, R₂, R₄, R₆) and base clock biases from actual pseudoranges (R0, R2, R4, R6).

Claim 8

Dependent Claim 29 words

A system according to claim 4, wherein the differential bias comprises a parabolic bias computed by using a parabolic model constructed over a time period from prior actual pseudoranges.

Claim 9

Dependent Claim 70 words

A system according to claim 4, wherein the differential bias is computed by deriving a difference between an estimated location of the reference receiver (316) and the known location of the reference receiver (316), the estimated location derived from a constellation of the sources (200-206, 624), the constellation used by the first positioning system (700) of the vehicle (102) to derive the first position estimate (716) of the vehicle (102).

Claim 10

Dependent Claim 23 words

A system according to claim 5, wherein the GPS processor (710) comprises a first Kalman filter (802) for filtering the first signals (110).

Claim 11

Dependent Claim 29 words

A system according to claim 6, wherein the main processor (1004) includes software further comprising a weighted combiner (1204) coupled to the output of the second Kalman filter (802).

Claim 12

Dependent Claim 25 words

A system according to claim 10, wherein the first Kalman filter (802) modifies its acceptable data perturbations depending on the velocity of the vehicle (102).

Claim 13

Dependent Claim 65 words

A system according to claim 10, wherein the processing system (1002, 1004, 1020) adapted to compute the third position estimate continuously communicates vehicle velocity data (1018) to the first Kalman filter (802) of the first positioning system (700), the first Kalman filter (802) using the vehicle velocity data to thereby enhance the accuracy of the first position estimate (716) of the first positioning system (700).

Claim 14

Dependent Claim 74 words

A computer-based method for autonomously navigating a vehicle (102) along a predetermined path, the method comprising the steps of: determining a location of the vehicle (102) using a terrestrial position determining system (200-206, 624), an inertial reference unit (904), and a vehicle odometer (902); causing (5306) the vehicle (102) to track the predetermined path based upon the location; and causing (4150) the vehicle (102) to detect and avoid obstacles while tracking the predetermined path.

Claim 15

Dependent Claim 93 words

A method according to claim 14, wherein the location determining step comprises the steps of: deriving a first position estimate (716) of the vehicle (102) based on first signals (110) from the terrestrial position determinating system (200-206, 624); deriving a second position estimate (908, 910) of the vehicle (102) based on second signals (908, 910) obtained from the inertial reference unit (904) mounted on the vehicle (102) and the vehicle odometer (902); and deriving the location of the vehicle (102) from the first position estimate (716) and the second position estimate (908, 910).

Claim 16

Dependent Claim 65 words

A method according to claim 14, wherein the location determining step comprises the steps of: receiving signals from the terrestrial position determining system (200-206, 624) at a reference position; processing the signals at the reference position to determine a differential bias; communicating the differential bias from the reference position to the vehicle; and processing the differential bias at the vehicle to accurately determine the location.

Claim 17

Dependent Claim 71 words

A method according to claim 14, wherein the location determining step comprises the steps of: anticipating (1304, 1306) the relative position of satellites (200-206) of the terrestrial position determining system with respect to the location based upon data in an almanac; selecting (1312) a best constellation of the satellites (200-206) based on the geometry of the satellites (200-206) relative to the location; and recognizing (1314) only signals from the best constellation.

Claim 18

Dependent Claim 67 words

A method according to claim 15, wherein the first position estimate derivation step comprises the steps of: incorporating (1906) previous first position estimates into a best fit algorithm; monitoring (1908) the best fit algorithm until the statistical R squared value of the best fit algorithm is greater than or equal to a preselected threshold 0.98; and extrapolating (1916) the first position estimate from the best fit algorithm.

Claim 19

Dependent Claim 91 words

A method according to claim 15, wherein the first position estimate derivation step comprises the steps of: deriving (2104) actual pseudoranges of satellites (200-206) of the terrestrial position determining system using almanac data; computing (2104) estimated pseudoranges of the satellites (200-206) using ephemeris data; comparing (2106) the differences between the actual pseudoranges and the estimated pseudoranges against a preselected threshold; adopting (2108) the estimated pseudoranges if the differences are greater than the preselected threshold; otherwise, adopting (2110) the actual pseudoranges; and using the adopted pseudoranges to compute the first position estimate.

Claim 20

Dependent Claim 95 words

A method according to claim 15, further comprising the steps of: transmitting the second signals (908, 910) (1010) to a second Kalman filter (1202); outputting the second position estimate from the second Kalman filter (1202) to a weighted combiner (1204); outputting from the weighted combiner (1204) a vehicle velocity (1018) of the vehicle (102) to a first Kalman filter (802) of the first positioning system; and adapting the first Kalman filter (802) pursuant to the vehicle velocity (1018) to increase the accuracy of the first position estimate (1006) outputted from the first Kalman filter (802).

Claim 21

Dependent Claim 36 words

A method according to claim 20, wherein the weighted combiner output step further comprises the step of outputting weighted data (1206) to the second Kalman filter (1202) to increase the accuracy of the second position estimate.

Claim 22

Dependent Claim 27 words

A method according to claim 15, wherein the weighted combiner output step further comprises the step of outputting weighted data (1016) to a vehicle navigator (406, 1022).

Claim 23

Dependent Claim 85 words

A method according to claim 16, wherein the signal processing step comprises the steps of: obtaining (1706) the known position of the reference position (316); computing (1706) reference antenna pseudoranges (R₀, R₂, R₄, R₆) for sources (200-206, 624) of the terrestrial position determining system in view of the reference position (316); deriving (1708) an estimated position of the reference position (316) using the reference antenna pseudoranges (R₀, R₂, R₄, R₆); and comparing (1710) the estimated position with the exact position to derive the differential bias.

Claim 24

Dependent Claim 108 words

A method according to claim 16, wherein the signal processing step includes the steps of: computing actual pseudoranges (R₀, R₂, R₄, R₆) for sources (200-206, 624) of the terrestrial positioning determining system in view of a reference antenna (316) at the reference position until a time when a parabolic model can be constructed based on the actual pseudoranges (R₀, R₂, R₄, R₆) with a preselected statistical R₂ value; extrapolating estimated pseudoranges (R₀, R₂, R₄, R₆) of the sources (200-206, 624) at future times from the parabolic models; and computing differential biases by comparing the actual pseudoranges (R₀, R₂, R₄, R₆) and the estimated pseudoranges (R₀, R₂, R₄, R₆).

Claim 25

Dependent Claim 84 words

A navigation system (406), adapted for use with autonomous operation of a surface based vehicle (102) of the type having an instantaneous center to which all motions can be referenced, for example, conventionally steered, articulated, omni-directional, or skid-steered, exhibiting either oversteer or understeer characteristics, which comprises: first means (5306) for compensating for latency effects among dynamic effects of the vehicle (102), the first means using feedforward compensation; and second means (5306) for compensating for other dynamic effects of the vehicle (102) using feedback compensation.

Claim 26

Dependent Claim 26 words

A navigation system (406) acording to claim 25, wherein the first means (5306) comprises means (5306) for using an early steering command for the feedforward compensation.

Claim 27

Dependent Claim 39 words

A navigation system (406) according to claim 26, wherein the means (5306) for using an early steering command comprises means (5306) for using a preselected number of time constants of the latency effect to advance the early steering command.

Claim 28

Dependent Claim 25 words

A navigation system (406) according to claim 27, wherein the second means (5306) comprises means (5306) for using a quintic polynomial for the feedback compensation.

Claim 29

Dependent Claim 37 words

A navigation system (406) according to claim 28, wherein the means (5306) for using a quintic polynomial comprises means (5306) for replanning a simple continuous path that converges to a desired path at some lookahead distance (3310).

Claim 30

Dependent Claim 30 words

A navigation system (406) according to claim 29, wherein the means (5306) for replanning comprises means (5306) for converging to the desired path in a variable, speed-dependant lookahead distance (3310).

Claim 31

Dependent Claim 78 words

A navigation method (406), adapted for use with autonomous operation of a surface based vehicle (102) of the type having an instantaneous center to which all motions can be referenced, for example, conventionally steered, articulated, omni-directional, or skid-steered, exhibiting either oversteer or understeer characteristics, which comprises the steps of: compensating (5306) for latency effects among dynamic effects of the vehicle (102) using feedforward compensation; and compensating (5306) for other dynamic effects of the vehicle (102) using feedback compensation.

Claim 32

Dependent Claim 28 words

A navigation method (406) according to claim 31, wherein the step of compensating (5306) using feedforward compensation comprises: using (5306) an early steering command for the feedforward compensation.

Claim 33

Dependent Claim 37 words

A navigation method (406) according to claim 32, wherein the step of using (5306) an early steering command comprises using (5306) a preselected number of time constants of the latency effect to advance the early steering command.

Claim 34

Dependent Claim 27 words

A navigation method (406) according to claim 31, wherein the step of compensating (5306) using feedback compensation comprises using (5306) a quintic polynomial for the feedback compensation.

Claim 35

Dependent Claim 36 words

A navigation method (406) according to claim 34, wherein the step of using (5306) a quintic polynomial comprises replanning (5306) a simple continuous path that converges to a desired (3312) path at some lookahead distance (3310).

Claim 36

Dependent Claim 29 words

A navigation method (406) according to claim 35, wherein the step of replanning (5306) comprises converging (5306) to the desired path (3312) in a variable, speed-dependant lookahead distance (3310).

Claim 37

Dependent Claim 179 words

An autonomously navigated surface based vehicle (102) including a system for controlling the vehicle (102), the system comprising: first means (4302) for managing the system for controlling the vehicle, responsive to commands from either a vehicle navigation system (406) or a remote control panel (410); second means (4304) for controlling speed of the vehicle (102) in response to commands from the first means (4302); third means (4306) for controlling steering of the vehicle (102) in response to commands from the first means (4302); fourth means (4308) for controlling auxiliary functions of the vehicle (102) in response to commands from the first means (4302); fifth means (4310) for monitoring the vehicle's status and the operation of the first (4302) through fourth means (4308) in response to commands from the first means (4302); first bus means (4314) for interconnecting the first (4302) through fifth means (4310); and shutdown means (4312), connected to the first (4302) through fifth means (4310), for shutting down the vehicle (102) in response to an error condition in any of the first (4302) through fifth means (4310).

Claim 38

Dependent Claim 131 words

An autonomously navigated surface based vehicle (102) including a method of controlling the vehicle (102), the method comprising the steps of: high level controlling (4302) vehicle subsystems, responsive to commands from either a vehicle navigation system (406) or a remote control panel (410); controlling (4304) vehicle speed in response to the high level controlling vehicle subsystems (4302); controlling (4306) steering of the vehicle (102) in response to the high level controlling vehicle subsystem (4302); controlling (4308) auxiliary functions of the vehicle (102) in response to the high level controlling vehicle subsystems (4302); monitoring (4310) the vehicle's status and the operation of the preceding steps in response to the high level controlling vehicle subsystems (4302); shutting down (4312) the vehicle (102) in response to an error condition in any of the steps.

Claim 39

Dependent Claim 146 words

A tele-operation system (4406) for a surface based vehicle (102) comprising: control panel means (410) for providing a user of the system hand actuated controls for controlling such things as speed (4502), steering (4504), horn, bed raising and lowering, and mode of operation of the vehicle (102); a first tele-radio transceiver means (4502), connected to communicate with the control panel means (410), for sending and receiving signals to and from a vehicle tele-radio transceiver means; the vehicle tele-radio transceiver means, connected to communicate with on-board vehicle subsystems (4302) such as to effect speed, steering, horn, bed raising and lowering, and mode of operation, for sending and receiving signals to and from the first tele-radio transceiver means (4502); and identification means for identifying uniquely a vehicle (102) to be controlled so that communication and control by the system (4406) is only effectuated with an intended vehicle (102).

Claim 40

Dependent Claim 115 words

A tele-operation method (4406) for a surface based vehicle (102) comprising the steps of: providing a user of the method (4406) hand actuated controls (410) for controlling such things as speed (4502), steering (4504), horn, bed raising and lowering, and mode of operation of the vehicle (102); identifying uniquely a vehicle (102) to be controlled so that communication and control by the method (4406) is only effectuated with an intended vehicle (102); sending and receiving signals between a pair of tele-radio transceivers connected to communicate with the hand actuated controls (410) and on-board vehicle subsystems (4302) of an identified vehicle (102), such as effect speed, steering, horn, bed raising and lowering, and mode of operation.

Claim 41

Dependent Claim 59 words

A surface based vehicle control system comprising: means (4402) for providing for manual operation of the vehicle (102); means (4406) for providing for tele-operation of the vehicle (102); means (4408) for providing for autonomous operation of the vehicle (102); and means (4404) for providing for an orderly transition between manual operation, tele-operation, and autonomous operation of the vehicle (102).

Claim 42

Dependent Claim 54 words

A surface based vehicle control method comprising the steps of: providing (4402) for manual operation of the vehicle (102); providing (4406) for tele-operation of the vehicle (102); providing (4408) for autonomous operation of the vehicle (102); and providing (4404) for an orderly transition between manual operation, tele-operation, and autonomous operation of the vehicle (102).

Claim 43

Independent Claim 169 words

A method of navigation (406) adapted for use with a surface based vehicle (102) of the type having an instantaneous center to which all motions can be referenced, for example, conventionally steered, articulated, omni-directional, or skid-steered, exhibiting either oversteer or understeer characteristics, to follow a predetermined path (3312), which method (406) comprises the steps of: retrieving (3622) from a table (3010) a given posture comprising a reference path curvature, a maximum velocity, a desired heading, and desired vehicle position coordinates of the predetermined path (3312); determining (5306) a reference steering angle from the reference path curvature; determining (5306) a posture error; determining (5306) a desired steering angle from the reference steering angle and the posture error ; using (5306) the desired steering angle to direct the vehicle (102) toward the predetermined path (3312); determining (5306) a commanded speed less than the maximum velocity independently of the preceding steps; and using (5306) the commanded speed to control the speed of the vehicle (102), including stopping the vehicle (102) if necessary.

Claim 44

Dependent Claim 33 words

A method (406) according to claim 43, further comprising the step of safely controlling lateral acceleration during turning by modifying the maximum velocity by referring to the reciprocal of the desired steering angle.

Claim 45

Dependent Claim 74 words

A method (406) according to claim 43, further comprising the steps of: determining a vehicle stopping distance from an actual vehicle speed and a specified maximum vehicle deceleration value; performing (4150) detection of an object (4002) using range data at a distance greater than the vehicle stopping distance; and modifying (4150) the commanded speed in accordance with distance to the object (4002), thereby enabling the vehicle (102) to stop before contacting the object (4002).

Claim 46

Dependent Claim 39 words

A method (406) according to claim 43, wherein the step of determining a commanded speed comprises: monitoring speed setpoints commanded by a host computer (402) or a vehicle obstacle detection system (4150); and choosing the smallest of the setpoints.

Claim 47

Dependent Claim 169 words

A navigation system (406) adapted for a surface based vehicle (102) of the type having an instantaneous center to which all motions can be referenced, that is, conventionally steered, articulated, omni-directional, or skid-steered, exhibiting either oversteer or understeer characteristics, to follow a predetermined path (3312), which system (406) comprises: means (5306) for retrieving from a table (3010) a given posture comprising reference path curvature, maximum velocity, desired heading, and desired vehicle position coordinates of the predetermined path (3312); means (5306) for determining a reference steering angle from the reference path curvature; means (5306) for determining a posture error; means (5306) for determining a desired steering angle from the reference steering angle and the posture error; means (5306) for using the desired steering angle to direct the vehicle (102) toward the predetermined path (3312); means (5306) for independently determining a commanded speed less than the maximum velocity; and means (5306) for using the commanded speed to control the speed of the vehicle (102), including stopping the vehicle (102) if necessary.

Claim 48

Dependent Claim 32 words

A system (406) according to claim 47, further comprising means for safely controlling lateral acceleration during turning by modifying the maximum velocity by referring to the reciprocal of the desired steering angle.

Claim 49

Dependent Claim 76 words

A system (406) according to claim 47, further comprising: means for determining a vehicle stopping distance from an actual vehicle speed and a specified maximum vehicle deceleration value; means (4150) for performing detection of an object (4002) using range data at a distance greater than the vehicle stopping distance; and means for modifying the commanded speed in accordance with distance to the object (4002), thereby enabling the vehicle (102) to stop before contacting the object (4002).

Claim 50

Dependent Claim 43 words

A system (406) according to claim 47, wherein the means for determining a commanded speed comprises: means for monitoring speed setpoints commanded by a host computer (402) or a vehicle obstacle detection system (4150); and means for choosing the smallest of the setpoints.

Claim 51

Dependent Claim 97 words

A navigation method (406) adapted for a surface based vehicle (102) of the type having an instantaneous center to which all motions can be referenced,that is, conventionally steered, articulated, omni-directional, or skid-steered, exhibiting either oversteer or understeer characteristics, the vehicle (102) to travel over a route (3312), the method (406) comprising the steps of: manually driving the vehicle (102) over the route (3312) to collect driven data; smoothing out the driven data to produce smoothed data comprising a consistent path; using (5306) the smoothed data comprising a consistent path to navigate the vehicle (102) over the route.

Claim 52

Dependent Claim 49 words

A navigation method (406) according to claim 51, wherein the step of smoothing out the driven data further comprises the step of performing an integration function on the driven data, thereby smoothing the driven data so that measured vehicle position, heading and curvature are consistent along the route (3312).

Claim 53

Dependent Claim 100 words

A navigation system (406) adapted for a surface based vehicle (102) of the type having an instantaneous center to which all motions can be referenced, that is, conventionally steered, articulated, omni-directional, or skid-steered, exhibiting either oversteer or understeer characteristics, the vehicle (102) to travel over a route (3312), the system (406) comprising: means for manually driving the vehicle over the route to collect driven data; means for smoothing out the driven data to produce smoothed data comprising a consistent path; means (5306) for using the smoothed data comprising a consistent path to navigate the vehicle (102) over the route (3312).

Claim 54

Dependent Claim 47 words

A navigation system (406) according to claim 53, wherein the means for smoothing out the driven data further comprises means for performing an integration function on the driven data, thereby smoothing the driven data so that measured vehicle position, heading and curvature are consistent along the route.

Claim 55

Independent Claim 163 words

A method of tracking (5306) a desired path (3312) for an autonomous surface based vehicle (102) comprising the steps of: determining reference postures (3202, 3214, 3220) at regular unit distances along a desired path (3312), where postures are packets of information about a particular location on the path including longitude, latitude, heading, curvature, maximum velocity, and distance to the next posture; determining an actual vehicle posture (3210, 3212, 3218) based on the reference postures (3202, 3214, 3220); determining an expected vehicle posture (3216) at a future time corresponding to a current planning time interval based on the actual vehicle posture (3210, 3212, 3218); determining a desired posture (3204, 3212, 3218) at the end of a next planning time interval; determining a steering angle (3112) from the expected vehicle posture (3216) and the desired posture (3212, 3218); commanding the vehicle (102) to steer the determined steering angle (3206, 3208); and repeating the steps from the actual vehicle posture determining step to vehicle commanding step.

Claim 56

Independent Claim 157 words

A system for tracking (5306) a desired path (3312) for an autonomous surface based vehicle (102) comprising: means for determining reference postures (3202, 3214, 3220) at regular unit distances along a desired path (3312), where postures are packets of information about a particular location on the path including longitude, latitude, heading, curvature, maximum velocity, and distance to the next posture; means for determining an actual vehicle posture (3210, 3212, 3218) based on the reference postures (3202, 3214, 3220); means for determining an expected vehicle posture (3216) at a future time corresponding to a current planning time interval based on the actual vehicle posture (3210, 3212, 3218); means for determining a desired posture (3204, 3212, 3218) at the end of a next planning time interval; means for determining a steering angle (3112) from the expected vehicle posture (3216) and the desired posture (3212, 3218); means for commanding the vehicle (102) to steer the determined steering angle (3206, 3208).

Claim 57

Independent Claim 78 words

A system (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) comprising: means for executing vehicle commands causing the vehicle (102) to attempt to follow the preset path (3312); means for periodically calculating errors in following the preset path (3312); means, responsive to the calculated errors, for adjusting the vehicle commands to reduce the calculated errors, whereby the vehicle (102) tracks the preset path (3312) with a high degree of accuracy.

Claim 58

Dependent Claim 84 words

The system (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) of claim 57, wherein the vehicle commands comprise separate steering and speed control aspects, and the means for executing vehicle commands causing the vehicle (102) to attempt to follow the preset path (3312) comprises: means (3102, 3104, 3110) for executing the steering control aspects; and means (3106, 3108, 3110) for executing the speed control aspects, whereby steering and speed control of the vehicle (102) are decoupled.

Claim 59

Dependent Claim 72 words

A system (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 57, wherein the means, responsive to the calculated errors, for adjusting the vehicle commands to reduce the calculated errors, includes means for constructing a smooth path back to the preset path (3312) using a quintic polynomial, whereby the vehicle (102) tracks the preset path (3312) with a high degree of accuracy.

Claim 60

Dependent Claim 89 words

A system (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 57, wherein the means, responsive to the calculated errors, for adjusting the vehicle commands to reduce the calculated errors, includes means for constructing a smooth path back to the preset path (3312) using a quintic polynomial and means for compensating for vehicle response characteristics, the vehicle response characteristics including latency of vehicle control commands, slow system response and vehicle dynamics including vehicle-ground interaction, slip angle and under/over steering.

Claim 61

Dependent Claim 54 words

A system (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 60, wherein the means, responsive to the calculated errors, for adjusting the vehicle commands to reduce the calculated errors, further includes means for compensating for sensing and actuation timing characteristics of the system.

Claim 62

Dependent Claim 59 words

A system (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 60, wherein the means, responsive to the calculated errors, for adjusting the vehicle commands to reduce the calculated errors, further includes means for varying a look-ahead distance (3310) based on the speed of travel of the vehicle (102).

Claim 63

Dependent Claim 54 words

A system (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 60, wherein the means, responsive to the calculated errors, for adjusting the vehicle commands to reduce the calculated errors, further includes means for adjusting control of the vehicle using an optimal control system.

Claim 64

Independent Claim 77 words

A method (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312), the method comprising the steps of: executing vehicle commands causing the vehicle (102) to attempt to follow the preset path (3312); periodically calculating errors in following the preset path (3312); adjusting, responsive to the calculated errors, the vehicle commands to reduce the calculated errors; whereby the vehicle (102) tracks the preset path (3312) with a high degree of accuracy.

Claim 65

Dependent Claim 81 words

A method (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 64, wherein the vehicle commands comprise separate steering and speed control aspects, and the step of executing vehicle commands causing the vehicle (102) to attempt to follow the preset path (3312) comprises: executing (3102, 3104, 3110) the steering control aspects; and executing (3106, 3108, 3110) the speed control aspects; whereby steering and speed control of the vehicle (102) are decoupled.

Claim 66

Dependent Claim 73 words

A method (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 64, wherein the step of adjusting, responsive to the calculated errors, the vehicle commands to reduce the calculated errors, includes the step of: constructing a smooth path back to the preset path (3312) using a quintic polynomial; whereby the vehicle (102) tracks the preset path (3312) with a high degree of accuracy.

Claim 67

Dependent Claim 88 words

A method (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 64, wherein the step of adjusting, responsive to the calculated errors, the vehicle commands to reduce the calculated errors, includes the steps of: constructing a smooth path back to the preset path (3312) using a quintic polynomial; and compensating for vehicle response characteristics, the vehicle response characteristics including latency of vehicle control commands, slow system response and vehicle dynamics including vehicle-ground interaction, slip angle and under/over steering.

Claim 68

Dependent Claim 56 words

A method (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 67, wherein the step of adjusting, responsive to the calculated errors, the vehicle commands to reduce the calculated errors, further includes the step of: compensating for sensing and actuation timing characteristics of the method (5306).

Claim 69

Dependent Claim 60 words

A method (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 67, wherein the step of adjusting, responsive to the calculated errors, the vehicle commands to reduce the calculated errors, further includes the step of varying a look-ahead distance (3310) based on the speed of travel of the vehicle (102).

Claim 70

Dependent Claim 54 words

A method (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) according to claim 67, wherein the step of adjusting, responsive to the calculated errors, the vehicle (102) commands to reduce the calculated errors, further includes adjusting control of the vehicle (102) using an optimal control method.

Claim 71

Independent Claim 169 words

A system (5306) for a vehicle (102) for enabling the vehicle (102) to track a preset path (3312) comprising: means (3102) for planning steering, by outputting a desired steering angle (3112), based on a desired path input from a supervisory system and sensed vehicle positions input (3114) from a positioning system (1000); means (3104) for controlling steering of the vehicle (102), by outputting steering servo commands to a steering system (3104) of the vehicle, responsive to the output (3112) of the means for planning steering (3102) and to feedback (3116) from the steering system (3110) of the vehicle; means for setting speed (3106), by outputting a desired speed signal, based on a desired speed input from the supervisory system; and means for controlling the speed (3108) of the vehicle (102), by outputting speed commands to a vehicle speed system (3110), responsive to the output of the means for setting speed (3106) and feedback (3118) from the vehicle speed system (3110), whereby a path tracking control structure (3100) is realized.

Claim 72

Independent Claim 171 words

A method of operating a system (5306) for a vehicle (102) for enabling the vehicle to track a preset path (3312) comprising the steps of: planning steering (3102), by outputting a desired steering angle (3112), based on a desired path input from a supervisory system and sensed vehicle positions input (3114) from a positioning system (1000); controlling steering (3104) of the vehicle (102), by outputting steering servo commands to a steering system (3104) of the vehicle (102), responsive to the output (3112) of the step of planning steering (3102) and to feedback (3116) from the steering system (3110) of the vehicle (102); setting speed (3106), by outputting a desired speed signal (3130), based on a desired speed input from the supervisory system; and controlling the speed (3108) of the vehicle (102), by outputting speed commands to a vehicle speed system (3110), responsive to the output of the step of setting speed (3106) and feedback (3118) from the vehicle speed system (3110), whereby a path tracking control structure (3100) method is realized.

Claim 73

Independent Claim 93 words

A system (406) for enabling a vehicle (102) to traverse a predetermined route (3312) by generating a series of paths to be tracked, the system including a system for generating the paths comprising: means for storing route data representing beginning and ending points on a predetermined route (3312); means for storing sets of compressed path data for each predetermined route (3312); means for successively retrieving sets of compressed path data associated with a predetermined route (3312); and means for successively generating a continuous path from each of the sets of compressed path data.

Claim 74

Dependent Claim 77 words

A system for generating paths according to claim 73, wherein the compressed path data for each predetermined route is comprised of nodes (2202), lines (2204), and arcs (2210), and the means for successively generating a path from each of the sets of compressed path data includes means to select a series of nodes, means to connect the series of nodes using lines, arcs, or both, and means to compile a set of points along the connected nodes.

Claim 75

Dependent Claim 22 words

A system for generating paths according to claim 73, wherein the compressed path data for each predetermined route is comprised of B-splines.

Claim 76

Dependent Claim 24 words

A system for generating paths according to claim 73, wherein the compressed path data for each predetermined route is comprised of clothoid curves (2602).

Claim 77

Dependent Claim 89 words

system (406) for enabling a vehicle (102) to traverse a predetermined route (3312) by generating a series of paths to be tracked, the system employing a method for generating the paths, the method comprising the steps of: storing route data representing beginning and ending points on a predetermined route (3312); storing sets of compressed path data for each predetermined route (3312); successively retrieving sets of compressed path data associated with a predetermined route (3312); and successively generating a continuous path from each of the sets of compressed path data.

Claim 78

Dependent Claim 76 words

A method for generating paths according to claim 77, wherein the stored compressed path data for each predetermined route is comprised of nodes (2202), lines (2204), and arcs (2210), and the step of successively generating a continuous path from each of the sets of compressed path data includes the steps of: selecting a series of nodes; connecting the series of nodes using lines, arcs, or both, and; compiling a set of points along the connected nodes.

Claim 79

Dependent Claim 23 words

A method for generating paths according to claim 77, wherein the stored compressed path data for each predetermined route is comprised of B-splines.

Claim 80

Dependent Claim 25 words

A method for generating paths according to claim 77, wherein the stored compressed path data for each predetermined route is comprised of clothoid curves (2602).

Claim 81

Dependent Claim 48 words

A system according to claim 37, including an automatic obstacle handling system, the system comprising: means (404), mounted on the vehicle (102), for automatically detecting obstacles (4002) in a path (3312) of the vehicle (102); and means for causing the vehicle (102) to automatically avoid the obstacles (4002).

Claim 82

Dependent Claim 64 words

A system according to claim 81, wherein the means (404) for detecting obstacles comprises: means (4222) for transmitting energy some distance along the path (3312) of the vehicle (102); means (4222) for receiving that portion of the transmitted energy which is reflected back from potential obstacles (4002); and means (4212) for processing the portion which is reflected back to thereby detect actual obstacles (4002).

Claim 83

Dependent Claim 107 words

A system according to claim 82, wherein the means (4212) for processing the portion which is reflected back comprises: means for producing range data based on the reflected back portion; means for producing angular position data based on the reflected back portion and scanning data indicative of position in a scan cycle; means for producing cylindrical coordinate data based on the range data and the angular position data; and means for converting the cylindrical coordinate data into Cartesian coordinate data to thereby produce a road profile of the vehicle path (3312), whereby image data is compiled in frames and threatening obstacles (4002) are distinguished from natural objects.

Claim 84

Dependent Claim 63 words

A system according to claim 83, wherein the means (4212) for processing the portion which is reflected back further comprises: means for comparing expected road profiles, which have been previously stored, with the road profile produced; and means, responsive to the means for comparing, for signalling detection of an obstacle (4002) when the comparing means finds a difference exceeding a preset threshold value.

Claim 85

Dependent Claim 32 words

A system according to claim 83, wherein the means (4212) for processing the portion which is reflected back further comprises means for performing blob extraction on a full frame of image data.

Claim 86

Dependent Claim 58 words

A system according to claim 85, wherein the means for performing blob extraction comprises: means for clustering the data produced into groups based on height data; means for comparing an expected road height with the clustered data; and means for indicating detection of an obstacle (4002) when the means for comparing finds a difference exceeding a preset threshold.

Claim 87

Dependent Claim 42 words

A system according to claim 86, wherein the means for performing blob extraction further comprises means for accumulating a global obstacle map (4004) based on the detected obstacles (4002) whereby the global obstacle map (4004) is used in planning vehicle paths (3312).

Claim 88

Dependent Claim 74 words

A system according to claim 83, wherein the means (4212) for processing the portion which is reflected back further comprises means for selecting a relatively small amount of the data produced from the portion reflected back in order to minimize processing load, the data selected being associated with an area lying in the desired vehicle path at and beyond the vehicle's stopping distance, the selection of the area being affected by the vehicle speed.

Claim 89

Dependent Claim 76 words

A system according to claim 82, wherein the means (4222) for transmitting comprises means for scanning the path within a boundary zone, the boundary zone being equal in width to the width of the vehicle (102) plus a safety margin, and the boundary zone extending in front of the vehicle (102) from a distance equal to the vehicle's minimum stopping distance and to a distance less than or equal to the means for transmitting's maximum range.

Claim 90

Dependent Claim 42 words

A system according to claim 89, wherein the width of the boundary zone is determined according to the width of the vehicle path, and at least the length of the boundary zone varies with variations in the vehicle's speed and stopping distance.

Claim 91

Dependent Claim 24 words

A system according to claim 89, wherein the boundary zone's edges are found by transferring the range data to an image plane representation (3900).

Claim 92

Dependent Claim 67 words

A system according to claim 81, wherein the means for causing the vehicle (102) to avoid the obstacles (4002) comprises: means for immediately stopping the vehicle (102) before contact with any of the obstacles (4002) is made, if the contact is imminent; means for planning a path around the obstacles (4100); and means for causing the vehicle (102) to follow the planned path around the obstacles (4002).

Claim 93

Dependent Claim 74 words

A system according to claim 91, wherein the means for planning a path around the obstacles (4002) comprises: means for deciding which side of an obstacle (4002) the vehicle (102) should pass; and means for selecting subgoals which lead to a higher level goal, the subgoals representing points which define a path around the obstacle, the higher level goal being a return to an original path after the vehicle (102) avoids the obstacle (4002).

Claim 94

Dependent Claim 32 words

A method according to claim 38, including the steps of: automatically detecting obstacles (4002) in a path of the vehicle (102); and causing the vehicle (102) to automatically avoid the obstacles (4002).

Claim 95

Dependent Claim 55 words

A method according to claim 94, wherein the step of detecting obstacles (4002) comprises: transmitting energy some distance along the path (3312) of the vehicle (102); receiving that portion of the transmitted energy which is reflected back from potential obstacles (4002); and processing the portion which is reflected back to thereby detect actual obstacles (4002).

Claim 96

Dependent Claim 20 words

A system according to claim 82 or method according to claim 95, wherein the transmitted energy is electro-magnetic in nature.

Claim 97

Dependent Claim 19 words

A system or method according to claim 96, wherein the transmitted energy is electro-magnetic radiation in the infra-red spectrum.

Claim 98

Dependent Claim 24 words

A system or method according to claim 97, wherein the transmitted energy of electro-magnetic radiation in the infra-red spectrum is produced by a laser.

Claim 99

Dependent Claim 20 words

A system according to claim 82 or method according to claim 95, wherein the transmitted energy is acoustic in nature.

Claim 100

Dependent Claim 26 words

A system according to claim 81 or method according to claim 104, wherein the step of transmitting comprises scanning the path with a single scan line.

Claim 101

Dependent Claim 24 words

A system or method according to claim 100, wherein the single scan line does not contact the ground in front of the vehicle (102).

Claim 102

Dependent Claim 23 words

A system according to claim 82 or method according to claim 95, wherein the step of transmitting comprises scanning the path with multiple-lines.

Claim 103

Dependent Claim 42 words

A system according to claim 82 or method according to claim 95, wherein the step of processing the portion which is reflected back comprises: filtering the portion to discriminate between threatening obstacles (4002) and natural objects, including expected changes in road features.

Claim 104

Dependent Claim 30 words

A system or method according to claim 103, wherein the step of filtering the portion comprises varying the portion to be filtered based on the speed of the vehicle (102).

Claim 105

Dependent Claim 98 words

A method according to claim 95, wherein the step of processing the portion which is reflected back comprises: producing range data based on the reflected back portion; producing angular position data based on the reflected back portion and scanning data indicative of position in a scan cycle; producing cylindrical coordinate data based on the range data and the angular position data; and converting the cylindrical coordinate data into Cartesian coordinate data to thereby produce a road profile of the vehicle path (3312), whereby image data is compiled in frames and threatening obstacles (4002) are distinguished from natural objects.

Claim 106

Dependent Claim 58 words

A method according to claim 105, wherein the step of processing the portion which is reflected back further comprises: comparing expected road profiles, which have been previously stored, with the road profile produced; and responsive to the step of comparing, signalling detection of an obstacle (4002) when the comparing step finds a difference exceeding a preset threshold value.

Claim 107

Dependent Claim 29 words

A method according to claim 105, wherein the step of processing the portion which is reflected back further comprises performing blob extraction on a full frame of image data.

Claim 108

Dependent Claim 52 words

A method according to claim 107, wherein the step of performing blob extraction comprises: clustering the data produced into groups based on height data; comparing an expected road height with the clustered data; and indicating detection of an obstacle (4002) when the step of comparing finds a difference exceeding a preset threshold.

Claim 109

Dependent Claim 40 words

A method according to claim 108, wherein the step of performing blob extraction further comprises: accumulating a global obstacle map (4004) based on the detected obstacles (4002) whereby the global obstacle map (4004) is used in planning vehicle paths (3312).

Claim 110

Dependent Claim 71 words

A method according to claim 105, wherein the step of processing the portion which is reflected back further comprises: selecting a relatively small amount of the data produced from the portion reflected back in order to minimize processing load, the data selected being associated with an area lying in the desired vehicle path at and beyond the vehicle's stopping distance, the selection of the area being affected by the vehicle speed.

Claim 111

Dependent Claim 75 words

A method according to claim 95, wherein the step of transmitting comprises: scanning the path within a boundary zone, the boundary zone being equal in width to the width of the vehicle (102) plus a safety margin, and the boundary zone extending in front of the vehicle (102) from a distance equal to the vehicle's minimum stopping distance and to a distance less than or equal to a maximum range of transmission of the energy.

Claim 112

Dependent Claim 42 words

A method according to claim 111, wherein the width of the boundary zone is determined according to the width of the vehicle path, and at least the length of the boundary zone varies with variations in the vehicle's speed and stopping distance.

Claim 113

Dependent Claim 24 words

A method according to claim 112, wherein the boundary zone's edges are found by transferring the range data to an image plane representation (3900).

Claim 114

Dependent Claim 60 words

A method according to claim 94, wherein the step of causing the vehicle (102) to avoid the obstacles (4002) comprises: immediately stopping the vehicle (102) before contact with any of the obstacles (4002) is made, if the contact is imminent; planning a path around the obstacles; and causing the vehicle (102) to follow the planned path around the obstacles (4002).

Claim 115

Dependent Claim 70 words

A method according to claim 114, wherein the step of planning a path around the obstacles (4002) comprises: deciding which side of an obstacle (4002) the vehicle (102) should pass; and selecting subgoals which lead to a higher level goal, the subgoals representing points which define a path around the obstacle, the higher level goal being a return to an original path after the vehicle (102) avoids the obstacle (4002).

Claim 116

Dependent Claim 125 words

A scanning system (404) for detecting obstacles (4002) in a path (3312) of a vehicle (102), mounted on the vehicle (102), comprising: means (4222) for producing a beam of energy; means (4206) for scanning the beam of energy through a desired range of angles relative to the vehicle in cycles; means (4212, 4214, 4222, 4228) for measuring distances between the vehicle and objects in the path of the vehicle, comprised of means (4222) for detecting reflected energy, means (4212, 4214, 4226, 4228, 4230) for storing information associated with the reflected energy detected, during each of the scanning cycles; and means (4212) for calculating the distance the reflected energy detected has travelled by processing the associated information which is stored during each of the scanning cycles.

Claim 117

Dependent Claim 51 words

A scanning system (404) according to claim 116, further comprising means (4228) for disabling the means (4222) for producing a beam of energy if the operation of the means (4206) for scanning the beam of energy through a desired range of angles relative to the vehicle in cycles is substantially impaired.

Claim 118

Dependent Claim 63 words

A scanning system (404) according to claim 116, wherein the means for measuring distances (4212, 4214, 4222, 4228) between the vehicle (102) and objects (4002) in the path of the vehicle (102) further comprises: means (4228) for detecting substantial impairment of the means (4206) for scanning the beam of energy through a desired range of angles relative to the vehicle (102) in cycles.

Claim 119

Dependent Claim 52 words

A scanning system (404) according to claim 116, further comprising means (4228) for disabling the means (4222) for producing a beam of energy, during a portion of the scanning cycle, so that only a fraction of the total field of view is scanned, wherein the total amount of data transferred is minimized.

Claim 120

Dependent Claim 24 words

A scanning system (404) according to claim 116, further comprising means (4210) for varying the scanning cycles in number of scans per unit time.

Claim 121

Dependent Claim 22 words

A scanning system (404) according to claim 116, further comprising means (4210) for varying distance measurements per scan, thereby varying scanner resolution.

Claim 122

Dependent Claim 72 words

A scanning system (404) according to claim 116, wherein the means (4212, 4214, 4226, 4228, 4230) for storing information associated with the reflected energy detected further comprises: means (4228) for converting signals from TTL to differential type signals; means (4226) for transmitting the differential type signals to a temporary storage buffer (4214); and means (4230) for transmitting the differential type signals from the storage buffer (4214) to a host processing system (4212).

Claim 123

Dependent Claim 109 words

A scanning method (4150) of detecting obstacles (4002) in a path (3312) of a vehicle (102), using a scanner (404) mounted on the vehicle (102), comprising the steps of: producing a beam of energy; scanning the beam of energy through a desired range of angles relative to the vehicle in cycles; measuring distances between the vehicle and objects in the path of the vehicle, comprising the steps of: detecting reflected energy, storing information associated with the reflected energy detected, during each of the scanning cycles, and calculating the distance the reflected energy detected has travelled by processing the associated information which is stored during each of the scanning cycles.

Claim 124

Independent Claim 200 words

A system for navigating (406) a vehicle (102) along a route (3312) comprising: means for storing route data representing a predetermined route; means for storing path data for each predetermined route; means for selecting a predetermined route for the vehicle (102) to traverse; means for retrieving route data representing a selected predetermined route; means for retrieving path data for retrieved route data; means for generating a path from retrieved path data; means (5306) for associating vehicle commands with a generated path; means (5306) for executing associated vehicle commands causing the vehicle to attempt to follow a generated path; means (5306) for periodically calculating errors in following a generated path; means (5306), responsive to calculated errors, for adjusting the execution of associated vehicle commands to reduce the calculated errors so that the vehicle tracks a generated path with a high degree of accuracy; means (4150) for detecting obstacles in the vehicle's direction of travel; means (4150) for avoiding collision with the obstacles, comprising means for stopping the vehicle to prevent a collision with the obstacles and means for generating a path around the obstacles; whereby an autonomous system (406) for safely and efficiently navigating a vehicle along a route is realized.

Claim 125

Independent Claim 182 words

A method (406) of navigating a vehicle (102) along a route (3312) comprising the steps of: storing route data representing a predetermined route; storing path data for each predetermined route; selecting a predetermined route for the vehicle (102) to traverse; retrieving route data representing a selected predetermined route; retrieving path data for retrieved route data; generating a path from retrieved path data; associating (5306) vehicle commands with a generated path; executing (5306) associated vehicle commands causing the vehicle to attempt to follow a generated path; periodically calculating (5306) errors in following a generated path; adjusting (5306), responsive to calculated errors, the execution of associated vehicle commands to reduce the calculated errors so that the vehicle tracks a generated path with a high degree of accuracy; detecting (4150) obstacles (4002) in the vehicle's direction of travel; avoiding (4150) collision with the obstacles (4002) by stopping the vehicle to prevent a collision with the obstacles (4002), generating a path around the obstacles (4002), or performing both; whereby an autonomous method (406) of safely and efficiently navigating a vehicle (102) along a route is realized.

Claim 126

Dependent Claim 65 words

A method (406) of navigating a vehicle (102) along a route (3312) according to claim 125, wherein the step (5306) of periodically calculating errors in following a generated path comprises: determining the vehicle's actual position (3210, 3212, 3218); determining the vehicle's desired position (3204); and comparing the actual (3210, 3212, 3218) with the desired position (3204); thereby calculating the errors in following the generated path.

Claim 127

Dependent Claim 82 words

A method (406) of navigating a vehicle (102) along a route (3312) according to claim 125, wherein the step (5306) of adjusting, responsive to calculated errors, the execution of associated vehicle commands to reduce the calculated errors so that the vehicle tracks a generated path with a high degree of accuracy comprises dynamically determining a correcting steering angle so that the correcting steering angle causes the vehicle (102) to steer from an actual position (3210, 3212, 3218) to a desired position (3204).

Claim 128

Independent Claim 87 words

A system for an open-pit mining operation for autonomously hauling material from a first site to a second site, the system comprising: a hauling vehicle; positioning means coupled to the vehicle for determining the position of the vehicle relative to the surface of the Earth; navigation means, coupled to the positioning means, for generating a route to be followed by the vehicle between the first site and the second site; and vehicle control means, responsive to the navigation means for causing the vehicle to follow the route.

Claim 129

Dependent Claim 86 words

A system according to claim 128, wherein the positioning means comprises: a first positioning system adapted to provide a first position estimate for the vehicle based on signals received from a satellite-based global positioning system; a second positioning system adapted to provide a second position estimate for the vehicle based on data obtained from an inertial reference device mounted on the vehicle; and a processing system adapted to compute a third position estimate for the vehicle from the first position estimate and the second position estimate.

Claim 130

Dependent Claim 23 words

A system according to claim 129, wherein the first positioning system comprises a receiver for receiving signals from NAVSTAR Global Positioning System (GPS).

Claim 131

Dependent Claim 33 words

A system according to claim 128, further comprising: detection means, coupled to the vehicle, for detecting obstacles along the route and for causing the vehicle to avoid the obstacles while following the route.

Claim 132

Dependent Claim 41 words

A system according to claim 128, wherein the navigation means comprises: an on-board navigation system coupled to the positioning means; an off-vehicle host processing system and; transceiver means for communicating data between the on-board navigation system and the host processing system.

Claim 133

Dependent Claim 58 words

A system according to claim 128, wherein the vehicle control means comprises: speed control means for controlling the speed of the vehicle; steering control means for controlling the steering of the vehicle; and vehicle manager means for receiving commands from the navigation means and for communicating the commands to the speed control means and the steering control means.

Claim 134

Independent Claim 17 words

A system according to any of claims 128 to 133, wherein a plurality of vehicles are employed.

Claim 135

Dependent Claim 17 words

An autonomous hauling vehicle for use in a system according to any of claims 128 to 134.

Integrated vehicle positioning and navigation system, apparatus and method

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