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US 5,495,251 AGranted
Method of and apparatus for cruise control
AssigneeLucas Industries public limited company
InventorsSimon P. Gilling, Douglas Ponsford, Reza Shokoufandeh
Life of this patent
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AssigneeLucas Industries public limited company
InventorsSimon P. Gilling, Douglas Ponsford, Reza Shokoufandeh
Estimating the term…
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 provides measurements of range and relative speed. The range measurement is compared by a subtracter 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. 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.
A cruise control apparatus for a vehicle, comprising a distant error calculator for determining a distance error as a difference between a desired distance between a target and the vehicle and an distance between the target and the vehicle, a speed error calculator for determining a speed error as a difference between a speed of the target and a speed of the vehicle, an acceleration demand calculator responsive to the distance error calculator and the speed error calculator, for producing a vehicle acceleration demand as a function of the distance error and the speed error, and an acceleration error calculator for producing an acceleration error as a difference between said acceleration demand and an actual vehicle acceleration.
A method of cruise control for a vehicle, comprising determining a distance error as a 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 a difference between a speed of the target and a speed of the vehicle, forming a vehicle acceleration demand as a function of the distance error and the speed error, and controlling the vehicle in accordance with an acceleration error formed as a difference between said acceleration demand and an actual vehicle acceleration.
Dependencies are inferred from the claim text.