System and method for automatically controlling vehicle speed to desired cruise speed with traction control function
First Claim
1. A system for automatically controlling a vehicle speed to a desired cruise speed, comprising:
- (a) first means for detecting a current vehicle speed;
(b) second means through which the current vehicle speed is set as a cruise speed at which the vehicle is desired to cruise;
(c) third means responsive to the cruise speed set through the second means for producing a speed control command to control an engine driving force generated by a vehicular engine so that the current vehicle speed coincides with the set cruise speed;
(d) fourth means responsive to the speed control command from the third means for actuating an engine driving force adjusting mechanism;
(e) fifth means for detecting an engine revolutional speed;
(f) sixth means for detecting a current operating variable of the engine driving force adjusting mechanism;
(g) seventh means for deriving an engine torque generated from the engine on the basis of the detected engine revolutional speed and the current operating variable;
(h) eighth means for deriving a running resistance on the basis of the derived engine torque and the current vehicle speed;
(i) ninth means for deriving a change in a predetermined factor determining the running resistance on the basis of the derived running resistance and determining, on the basis of the derived result of the change in the predetermined factor, whether a current road on which the vehicle cruises at the set cruise speed has a lower frictional coefficient than a predetermined value at which slips occur on drive wheels of the vehicle; and
(j) tenth means for producing an outputting a zero driving force command to the fourth means so that the engine driving force becomes zero via the engine driving force adjusting mechanism with the output of the speed command to the fourth means by the third means being halted according to the result determined by the ninth means.
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Accused Products
Abstract
A system and method for automatically controlling a vehicle speed to a desired cruise speed are disclosed in which when a vehicular running resistance is derived on the basis of an engine torque and change rate of the vehicle speed with time, the engine torque being derived on the basis of an engine revolutional speed and engine load, a predetermined factor determining the running resistance is derived on the basis of the running resistance. In addition, an absolute value of a difference of the predetermined factor from a previous predetermined factor derived one predetermined calculation period before is compared with a predetermined threshold value, a zero engine driving force command is outputted to an actuator of an engine driving force adjustng mechanism so that the engine driving force adjusting mechanism is actuated to zero the engine driving force to recover gripping forces of drive wheels when the absolute value of the difference exceeds the predetermined threshold value.
32 Citations
20 Claims
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1. A system for automatically controlling a vehicle speed to a desired cruise speed, comprising:
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(a) first means for detecting a current vehicle speed; (b) second means through which the current vehicle speed is set as a cruise speed at which the vehicle is desired to cruise; (c) third means responsive to the cruise speed set through the second means for producing a speed control command to control an engine driving force generated by a vehicular engine so that the current vehicle speed coincides with the set cruise speed; (d) fourth means responsive to the speed control command from the third means for actuating an engine driving force adjusting mechanism; (e) fifth means for detecting an engine revolutional speed; (f) sixth means for detecting a current operating variable of the engine driving force adjusting mechanism; (g) seventh means for deriving an engine torque generated from the engine on the basis of the detected engine revolutional speed and the current operating variable; (h) eighth means for deriving a running resistance on the basis of the derived engine torque and the current vehicle speed; (i) ninth means for deriving a change in a predetermined factor determining the running resistance on the basis of the derived running resistance and determining, on the basis of the derived result of the change in the predetermined factor, whether a current road on which the vehicle cruises at the set cruise speed has a lower frictional coefficient than a predetermined value at which slips occur on drive wheels of the vehicle; and (j) tenth means for producing an outputting a zero driving force command to the fourth means so that the engine driving force becomes zero via the engine driving force adjusting mechanism with the output of the speed command to the fourth means by the third means being halted according to the result determined by the ninth means. - View Dependent Claims (2, 3)
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4. A system for automatically controlling a vehicle speed to a desired cruise speed, comprising:
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(a) first means for detecting a current vehicle speed; (b) second means through which the current vehicle speed is set as a cruise speed at which the vehicle is desired to cruise; (c) thirds means responsive to the cruise speed set through the second means for producing a speed control command to control an engine driving force generated by a vehicular engine so that the current vehicle speed coincides with the set cruise speed; (d) fourth means responsive to the speed control command from the third means for actuating an engine driving force adjusting mechanism; (e) fifth means for detecting an engine revolutional speed; (f) sixth means for detecting a current operating variable of the engine driving force adjusting mechanism; (g) seventh means for deriving an engine torque generated from the engine on the basis of the detected engine revolutional speed and the current operating variable; (h) eighth means for deriving a running resistance on the basis of the derived engine torque and the current vehicle speed; and (i) ninth means for deriving a change in a predetermined factor determining the running resistance on the basis of the derived running resistance and determining, on the basis of the derived result of the change in the predetermined factor, whether a current road on which the vehicle cruises at the set cruise speed has a lower frictional coefficient than a predetermined value at which slips occur on drive wheels of the vehicle; and wherein the third means produces and outputs a zero driving force command to the fourth means so that the engine driving force becomes zero via the engine driving force adjusting mechanism in place of the output of the speed control command when the ninth means determines that the current road has a lower frictional resistance coefficient than the predetermined value. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method for automatically controlling a vehicle speed to a desired cruise speed, comprising the steps of:
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(a) detecting a current vehicle speed; (b) storing, through a setting means, the current vehicle speed as a target cruise speed at which the vehicle is desired to cruise; (c) producing a speed control command to control an engine driving force generated by a vehicular engine so that the current vehicle speed coincides with the stored cruise speed in response to the storage of the current speed carried out in the step (b); (d) actuating an engine driving force adjusting mechanism according to the speed control command; (e) detecting an engine revolutional speed; (f) detecting a current operating variable of the engine driving force adjusting mechanism; (g) deriving an engine torque generated from the vehicular engine on the basis of the detected engine revolutional speed and the detected current operating variable; (h) deriving a running resistance on the basis of the derived engine torque and current vehicle speed; (i) deriving a change in a predetermined factor determining the running resistance and determining, on the basis of the derived result of the change in the predetermined factor, whether a current road on which the vehicle cruises at the stored cruise speed has a lower frictional resistance coefficient than a predetermined value at which slips occur on drive wheels of the vehicle; and (j) producing and outputting a zero driving force command to actuate the engine driving force adjusting mechanism so that the engine driving force becomes zero by halting the output of the speed control command carried out in the step (c) according to the result of determination carried out in the step (i).
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Specification