Vehicle speed control system

A system for controlling a speed of a vehicle having a continuously variable transmission which transmits output torque generated by an internal combustion engine mounted on the vehicle to drive wheels of the vehicle, and a cruise controller which controls the speed of the vehicle to a desired speed in response to an instruction to cruise control inputted by a vehicle operator, comprising:

• operating condition detecting means for detecting operating conditions of the engine and the vehicle including at least an opening of a throttle valve and the speed of the vehicle;
• first shift controlling means for controlling a speed ratio of the continuously variable transmission based at least on the detected opening of the throttle valve and the detected speed of the vehicle;
• running resistance determining means for determining a running resistance acting on the vehicle;
• and
• second shift controlling means for controlling the speed ratio of the continuously variable transmission based at least on the determined running resistance and the detected speed of the vehicle;
• wherein
• the second shift controlling means controlling the speed ratio of the continuously variable transmission based at least on the determined running resistance and the detected speed of the vehicle, when the instruction to cruise control is inputted.

A method controlling a speed of a vehicle having a continuously variable transmission which transmits output torque generated by an internal combustion engine mounted on the vehicle to drive wheels of the vehicle, and a cruise controller which controls the speed of the vehicle to a desired speed in response to an instruction to cruise control inputted by a vehicle operator, comprising the steps of:

• detecting operating conditions of the engine and the vehicle including at least an opening of a throttle valve and the speed of the vehicle;
• smoothing the detected opening of the throttle valve;
• and
• controlling a speed ratio of the continuously variable transmission based at least on the detected opening of the throttle valve and the detected speed of the vehicle;
• wherein
• the step of shift control controlling the speed ratio of the continuously variable transmission based at least on the smoothed opening of the throttle valve and the detected speed of the vehicle, when the instruction to cruise control is inputted.

A method of controlling a speed of a vehicle having a continuously variable transmission which transmits output torque generated by an internal combustion engine mounted on the vehicle to drive wheels of the vehicle, and a cruise controller which controls the speed of the vehicle to a desired speed in response to an instruction to cruise control inputted by a vehicle operator, comprising the steps of:

• detecting operating conditions of the engine and the vehicle including at least an opening of a throttle valve and the speed of the vehicle;
• controlling a first speed ratio of the continuously variable transmission based at least on the detected opening of the throttle valve and the detected speed of the vehicle;
• determining a running resistance acting on the vehicle;
• and
• controlling a second speed ratio of the continuously variable transmission based at least on the determined running resistance and the detected speed of the vehicle;
• wherein
• the step of shift control controlling the second speed ratio of the continuously variable transmission based at least on the determined running resistance and the detected speed of the vehicle, when the instruction to cruise control is inputted.