EP0612641A1
Expired / Lapsed
EP
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Method of and apparatus for cruise control
Assignee: ZF International UK Ltd
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Filing: 1994-02-15
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Granted: —
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Expires: 2014-02-15
Abstract
Abstract A vehicle cruise controller is provided which monitors the range to and relative speed of a target vehicle ahead of the vehicle being controlled by the cruise controller. A radar (1) provides measurements of range and relative speed. The range measurement is compared by a subtracter (3) with a desired range which is a function of vehicle speed, so as to form a distance error. The relative speed signal represents a speed error. An acceleration demand is formed as a function, for example a weighted sum, of the distance and speed errors. More significance is given to the distance error when the target is relatively close. This is achieved by varying the gain of a multiplier (6). The acceleration demand may be supplied to vehicle brake and drive systems, but preferably the acceleration demand is compared with actual vehicle acceleration to provide the advantages of closed loop control.
Inventors
- 👤 Simon Peter Gilling
- 👤 Reza Shokoufandeh
- 👤 Douglas Ponsford
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 15:12
CPC Classifications
B; B60; B60W; B60W30/00; B60W30/14; B60W30/16; B60K; B60K31/00; B60K31/0008; B60K31/02; B60K31/04; B60K31/042; B60K31/045; B60K31/047; B60Q; B60Q9/00; B60Q9/008; G; G01; G01S; G01S13/00; G01S13/88; G01S13/93; G01S13/931; B60W50/00; B60W2050/0001; B60W2050/0002; B60W2050/0008; B60W2050/001; B60W2050/0011; B60W2050/0019; B60W2050/0022; B60W2520/00; B60W2520/10; B60W2554/00; B60W2554/80; B60W2554/801; B60W2554/802; B60W2720/00; B60W2720/10; B60W2720/106; G01S2013/93185; G01S2013/9319; G01S2013/932; G01S2013/9321; G01S2013/9324; G01S2013/9325; G01S2013/9327; G01S2013/93271
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
96 words
A cruise control apparatus for a vehicle, characterised by distance error determining means (1, 3, 4, 5) for determining a distance error as the difference between a desired distance between a target and the vehicle and the actual distance between the target and the vehicle, speed error determining means (1) for determining a speed error as the difference between the speed of the target and the speed of the vehicle, and acceleration demand producing means (2, 6, 7, 28) for producing a vehicle acceleration demand as a function of the distance error and the speed error.
Claim 2
Dependent Claim
57 words
A cruise control apparatus as claimed in Claim 1, characterised in that the vehicle acceleration demand producing means (2, 6, 7, 28) is arranged to calculate the vehicle acceleration demand as the sum of the product of the distance error and a first gain parameter and the product of the speed error and a second gain parameter.
Claim 3
Dependent Claim
31 words
A cruise control apparatus as claimed in Claim 1 or 2, characterised by further comprising desired distance determining means (4) for determining the desired distance as a function of vehicle speed.
Claim 4
Dependent Claim
67 words
A cruise control apparatus as claimed in Claim 2 or Claim 3 when dependent on Claim 2, characterised by further comprising gain setting means (2, 28) for setting at least one of the first and second gain parameters such that the quotient of the first gain parameter divided by the second gain parameter is a function of at least one of the distance and the distance error.
Claim 5
Dependent Claim
67 words
A cruise control apparatus as claimed in Claim 4, characterised in that the gain setting means (2) is arranged to set the quotient to a first value for a first distance error or a first actual distance and to a second value less than the first value for a second distance error or second actual distance greater than the first distance error or the first actual distance.
Claim 6
Dependent Claim
50 words
A cruise control apparatus as claimed in Claim 5, characterised in that the gain setting means (2) is arranged to set the quotient as a monotonically decreasing function of the distance error between the first and second distance errors or of the actual distance between the first and second distances.
Claim 7
Dependent Claim
68 words
A cruise control apparatus as claimed in any one of Claims 4 to 6, characterised in that the gain setting means (2, 28) is arranged to substantially halve the value of the quotient when the distance error is greater than a first predetermined distance error (T7) which is greater than zero and the speed error is greater than a first predetermined speed error which is greater than zero.
Claim 8
Dependent Claim
78 words
A cruise control apparatus as claimed in any one of the preceding claims, characterised by further comprising gating means (11, 12) for supplying the acceleration demand to a vehicle drive system when the acceleration demand is greater than a first threshold which is greater than or equal to zero, and for supplying the acceleration demand to a vehicle brake system when the acceleration demand is less than a second threshold which is less than or equal to zero.
Claim 9
Dependent Claim
75 words
A cruise control apparatus as claimed in Claim 8, characterised by further comprising inhibiting means (18-21) for inhibiting the supply of the acceleration demand to the vehicle brake system when the acceleration demand is greater than the second threshold (T2), the distance error is greater than a second predetermined distance error (T4) which is less than zero, and the speed error is greater than a second predetermined speed error (T3) which is less than zero.
Claim 10
Dependent Claim
41 words
A cruise control apparatus as claimed in any one of Claims 1 to 7, characterised by further comprising acceleration error producing means (8, 9) for producing an acceleration error as the difference between the acceleration demand and the actual vehicle acceleration.
Claim 11
Dependent Claim
82 words
A cruise control apparatus as claimed in Claim 10, characterised by further comprising gating means (11, 12) for supplying the acceleration error to a vehicle drive system (16) when the acceleration demand or error is greater than a first threshold (T1) which is greater than or equal to zero, and for supplying the acceleration error to a vehicle brake system (17) when the acceleration demand or error is less than a second threshold (T2) which is less than or equal to zero.
Claim 12
Dependent Claim
78 words
A cruise control apparatus as claimed in Claim 11, characterised by further comprising inhibiting means (18-21) for inhibiting the supply of the acceleration error to the vehicle brake system (17) when the acceleration demand or error is greater than the second threshold (T2), the distance error is greater than a second predetermined distance error (T4) which is less than zero, and the speed error is greater than a second predetermined speed error (T3) which is less than zero.
Claim 13
Dependent Claim
64 words
A cruise control apparatus as claimed in any one of Claims 1 to 9 for use in a vehicle driven by an internal combustion engine having a throttle controlled in cruise mode by an integrating controller (16), characterised by further comprising further gain setting means (13, 14) for multiplying the acceleration demand by a third gain parameter which is a function of vehicle speed.
Claim 14
Dependent Claim
66 words
A cruise control apparatus as claimed in any one of Claims 10 to 12 for use in a vehicle driven by an internal combustion engine having a throttle controlled in a cruise mode by an integrating controller (16), characterised by further comprising further gain setting means (13, 14) for multiplying the acceleration error by a third gain parameter which is a function of the vehicle speed.
Claim 15
Dependent Claim
41 words
A cruise control apparatus as claimed in Claim 13 or 14, characterised in that the third gain parameter has a constant value below a predetermined vehicle speed and a value which increases monotonically with vehicle speed above the predetermined vehicle speed.
Claim 16
Dependent Claim
49 words
A cruise control apparatus as claimed in any one of Claims 1 to 9 or 13 or 15 when dependent on 13, characterised by further comprising limiting means (10) for limiting the acceleration demand to less than a first positive demand threshold and greater than a negative demand threshold.
Claim 17
Dependent Claim
26 words
A cruise control apparatus as claimed in Claim 2 or any claim dependent on Claim 2, characterised in that the second gain parameter is a constant.
Claim 18
Dependent Claim
21 words
A cruise control apparatus as claimed in Claim 17, characterised in that the second gain parameter has a value of one.
Claim 19
Dependent Claim
32 words
A cruise control apparatus as claimed in any one of the preceding claims, characterised in that the distance to and relative speed of the target are measured using a radar system (1).
Claim 20
Independent Claim
78 words
A method of cruise control for a vehicle, comprising determining a distance error as the difference between a desired distance between a target and the vehicle and the actual distance between the target and the vehicle, determining a speed error as the difference between the speed of the target and the speed of the vehicle, and controlling the vehicle in accordance with a vehicle acceleration demand formed as a function of the distance error and the speed error.
Claim 21
Dependent Claim
43 words
A method as claimed in Claim 20, characterised in that the vehicle acceleration demand is calculated as the sum of the product of the distance error and a first gain parameter and the product of the speed error and a second gain parameter.
References Cited (Backward Citations)
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