System and method for automatically controlling a vehicle speed to a desired cruising speed

Claim 1

A system for automatically controlling a running speed of a moving object to a desired cruising speed, comprising: (a) first means for detecting the running speed of the moving object; (b) second means for operatively generating and outputting a command signal to run the moving object at a cruising speed, the cruising speed being a running speed at the time of the output of the command signal by the second means; (c) third mans for storing the cruising speed which comprises the running speed detected by the first means in response to the output of the command signal by the second means; (d) fourth means responsive to the command signal for suppressing an overshoot of the running speed to a minimum which occurs immediately after the second means generates and outputs the command signal, wherein the fourth means controls the running speed of the moving object with first control constants Ki, Gi in a control equation (Ki×α+ε)×Gi, wherein (ε) denotes a difference between the stored cruising speed and the running speed detected by the first means, (α) denotes a rate of change in the running speed detected by the first means, and said first control constant Gi denotes a control gain, until a predetermined condition is satisfied; and (e) fifth means for controlling the running speed so that the running speed is maintained at the stored cruising speed after the fourth means suppresses the overshoot and the predetermined condition is satisfied, wherein the fifth means controls the running speed of the moving object with second control constants K, G, which are different from and less than said first control constants Ki and Gi, in a control equation (Ki×α+ε)×G, wherein (ε) denotes a difference between the stored cruising speed and the running speed detected by the first means (α) denotes a rate of change in the running speed detected by the first means, and said second control constant G denotes a control gain.

Claim 2

A system for automatically controlling a running speed of a moving object to a desired cruising speed, comprising: (a) first means for detecting the running speed of the moving object; (b) second means for operatively generating and outputting a command signal to run the moving object at a cruising speed, the cruising speed being a running speed at the time of the output of the command signal by the second means; (c) third mans for storing the cruising speed which comprises the running speed detected by the first means in response to the output of the command signal by the second means; (d) fourth means responsive to the command signal for suppressing an overshoot of the running speed to a minimum which occurs immediately after the second means generates and outputs the command signal, wherein the fourth means controls the running speed of the moving object with first control constants Ki, Gi in a control equation (Ki×α+ε)×Gi, wherein (ε) denotes a difference between the stored cruising speed and the running speed detected by the first means, (α) denotes a rate of change in the running speed detected by the first means, and said first control constant Gi denotes a control gain, until a predetermined condition is satisfied; and (e) fifth means for controlling the running speed so that the running speed is maintained at the stored cruising speed after the fourth means suppresses the overshoot and the predetermined condition is satisfied, wherein the fifth means controls the running speed of the moving object with second control constants K, G, which are different from and less than said first control constants Ki and Gi, in a control equation (Ki×α+ε)×G, wherein (ε) denotes a difference between the stored cruising speed and the running speed detected by the first means (α) denotes a rate of change in the running speed detected by the first means, and said second control constant G denotes a control gain.

Claim 9

A method for automatically controlling a vehicle speed to a desired cruising speed, comprising the steps of: (a) detecting the vehicle speed: (b) generating and outputting a command signal to run the vehicle speed at a speed when an operation of a set switch is carried out; (c) storing the vehicle speed at which the vehicle cruises in response to the command signal outputted in the step (b); (d) suppressing an overshoot of the vehicle speed to a minimum, the overshoot occurring immediately after the vehicle speed is controlled to arrive at the stored vehicle speed in step (c) in accordance with a first predetermined control equation (Ki×α+ε)×Gi having first control constants Ki, Gi, wherein (α) denotes a difference between the stored cruising speed and the detected vehicle speed, (ε) denotes a rate of change in the detected vehicle speed and said first control constant Gi denotes a control gain, in response to the command signal outputted in the step (b); and (e) controlling the vehicle speed detected in the step (a) in accordance with a second predetermined control equation (Ki×α+ε)×G having second control constants K, G, which are different from and less than said first control constants Ki and Gi, wherein (α) denotes a difference between the stored cruising speed and the detected vehicle speed, (α) denotes a rate of change in the detected vehicle speed and said second control constant G denotes a control gain so that the vehicle speed coincides with the stored vehicle speed after the suppression of the overshoot in step (d); wherein steps (d) and (e) include controlling first and second valves operative with atmospheric and negative pressures to displace a throttle valve to open and closed positions in accordance with the first and second control equations.

Claim 10

A method for automatically controlling a vehicle speed to a desired cruising speed, comprising the steps of: (a) detecting the vehicle speed: (b) generating and outputting a command signal to run the vehicle speed at a speed when an operation of a set switch is carried out; (c) storing the vehicle speed at which the vehicle cruises in response to the command signal outputted in the step (b); (d) suppressing an overshoot of the vehicle speed to a minimum, the overshoot occurring immediately after the vehicle speed is controlled to arrive at the stored vehicle speed in step (c) in accordance with a first predetermined control equation (Ki×α+ε)×Gi having first control constants Ki, Gi, wherein (α) denotes a difference between the stored cruising speed and the detected vehicle speed, (ε) denotes a rate of change in the detected vehicle speed and said first control constant Gi denotes a control gain, in response to the command signal outputted in the step (b); and (e) controlling the vehicle speed detected in the step (a) in accordance with a second predetermined control equation (Ki×α+ε)×G having second control constants K, G, which are different from and less than said first control constants Ki and Gi, wherein (α) denotes a difference between the stored cruising speed and the detected vehicle speed, (α) denotes a rate of change in the detected vehicle speed and said second control constant G denotes a control gain so that the vehicle speed coincides with the stored vehicle speed after the suppression of the overshoot in step (d); wherein steps (d) and (e) include controlling first and second valves operative with atmospheric and negative pressures to displace a throttle valve to open and closed positions in accordance with the first and second control equations.

Claim 12

A system for a vehicle, comprising: (a) first means for detecting a current vehicle speed; (b) second means for operatively generating and outputting a cruise control command signal to set the current vehicle speed as a desired cruise speed; (c) third means responsive to the cruise control command signal for generating and outputting a first control command signal based on a first control equation (Ki×α+ε)×Gi that uses first control constants Ki, Gi, wherein (α) denotes a difference between the stored cruising speed and the detected vehicle speed, (ε) denotes a rate of change in the detected vehicle speed and said first control constant Gi denotes a control gain, immediately after receiving the cruise control command signal and a predetermined interval of time has passed, thereafter outputting a second control command signal based on a second control equation (Ki×α+ε)×G that uses second control constants K, G, wherein (α) denotes a difference between the stored cruising speed and the detected vehicle speed, (ε) denotes a rate of change in the detected vehicle speed and said second control constant G denotes a control gain, the first control constants being different from and larger than the second control constants; and (d) fourth means for adjusting an operating variable of an engine driving force adjusting mechanism of the vehicle in accordance with the first and second control command signals based on said first and second control equations so that an overshoot of the desired cruise speed during the transfer from a normal running operation to a cruise speed control operation is prevented and the vehicle speed is maintained at the cruise speed.

Claim 13

A system for a vehicle, comprising: (a) first means for detecting a current vehicle speed; (b) second means for operatively generating and outputting a cruise control command signal to set the current vehicle speed as a desired cruise speed; (c) third means responsive to the cruise control command signal for generating and outputting a first control command signal based on a first control equation (Ki×α+ε)×Gi that uses first control constants Ki, Gi, wherein (α) denotes a difference between the stored cruising speed and the detected vehicle speed, (ε) denotes a rate of change in the detected vehicle speed and said first control constant Gi denotes a control gain, immediately after receiving the cruise control command signal and a predetermined interval of time has passed, thereafter outputting a second control command signal based on a second control equation (Ki×α+ε)×G that uses second control constants K, G, wherein (α) denotes a difference between the stored cruising speed and the detected vehicle speed, (ε) denotes a rate of change in the detected vehicle speed and said second control constant G denotes a control gain, the first control constants being different from and larger than the second control constants; and (d) fourth means for adjusting an operating variable of an engine driving force adjusting mechanism of the vehicle in accordance with the first and second control command signals based on said first and second control equations so that an overshoot of the desired cruise speed during the transfer from a normal running operation to a cruise speed control operation is prevented and the vehicle speed is maintained at the cruise speed.