Automatic speed control for heavy vehicles

An automatic speed control system for a vehicle comprising:

• means for generating an actual speed signal proportional to the actual speed of the vehicle;
• means for generating a commanded speed signal proportional to the desired speed of the vehicle, including memory means, receiving the actual speed signal as an input, for storing a value of the actual speed signal in response to a signal indicating that an operator desires that the commanded speed signal be equivalent to the present actual speed of the vehicle;
• means for generating a speed error signal proportional to the difference between said actual and commanded speed signals;
• means for generating a control signal as a function of said speed error signal wherein said control signal regulates said actual vehicle speed to reduce said error signal;
• and
• means for limiting the commanded speed signal to a set value when it exceeds a predetermined limit, wherein said limiting means is disposed between said actual speed signal generating means and the input to said memory means, whereby said limiting means prevents an actual speed signal greater than said predetermined limit from being stored in said memory means.

An automatic speed control system for a vehicle comprising:

• means for generating an actual speed signal proportional to the actual speed of the vehicle;
• means for generating a commanded speed signal proportional to the desired speed of the vehicle, including memory means, receiving the actual speed signal as an input, for storing a value of the actual speed signal in response to a signal indicating that an operator desires that the commanded speed signal be equivalent to the present actual speed of the vehicle;
• means for generating a speed error signal proportional to the difference between said actual and commanded speed signals;
• means for generating a control signal as a function of said speed error signal wherein said control signal regulates said actual vehicle speed to reduce said error signal;
• means, receiving the actual speed signal as an input, for generating a resume speed signal to accelerate the vehicle to a speed value stored in said memory means subsequent to a brake application;
• and
• means for limiting the commanded speed signal to a set value when it exceeds a predetermined limit, wherein said limiting means is disposed between said actual speed signal and the input to said resume signal generating means.

An automatic speed control system for a vehicle comprising:

• means for generating an actual speed signal proportional to the actual speed of the vehicle;
• means for generating a commanded speed signal proportional to the desired speed of the vehicle;
• including memory means, receiving the actual speed signal as an input, for storing a value of the actual speed signal in response to a signal indicating that an operator desires that the commanded speed signal be equivalent to the present actual speed of the vehicle;
• means for generating a speed error signal proportional to the difference between said actual and commanded speed signals;
• means for generating a control signal as a function of said speed error signal wherein said control signal regulates said actual vehicle speed to reduce said error signal;
• means, receiving the actual speed signal as an input, for generating a resume speed signal to accelerate the vehicle to a speed value stored in said memory means subsequent to a brake application;
• and
• means for limiting the commanded speed signal to a set value when it exceeds a predetermined limit, wherein said limiting means is connected to receive the output of said memory means and limit the output to said set value when it exceeds said predetermined limit.

An automatic speed control system for a vehicle comprising:

• means for generating an actual speed signal proportional to the actual speed of the vehicle;
• means for generating a commanded speed signal proportional to the desired speed of the vehicle, including memory means, receiving the actual speed signal as an input, for storing a value of the actual speed signal in response to a signal indicating that an operator desires that the commanded speed signal be equivalent to the present actual speed of the vehicle;
• means for generating a speed error signal proportional to the difference between said actual and commanded speed signals;
• means for generating a control signal as a function of said speed error signal wherein said control signal regulates said actual vehicle speed to reduce said error signal;
• means, receiving the actual speed signal as an input, for generating a resume speed signal to accelerate the vehicle to a speed value stored in said memory means subsequent to a brake application;
• and
• means for limiting the commanded speed signal to a set value when it exceeds a predetermined limit, wherein said limiting means is connected to receive the resume speed signal and limit the signal to said set value when the signal exceeds said predetermined limit.