×

Electronic speed control system for automotive vehicles

  • US 4,325,336 A
  • Filed: 07/18/1980
  • Issued: 04/20/1982
  • Est. Priority Date: 07/20/1979
  • Status: Expired due to Term
First Claim
Patent Images

1. A speed control system for an automotive vehicle driven by an internal combustion engine under control of a throttle valve, the control system comprising:

  • first means for producing a timing signal with a period of time responsive to the actual speed of the vehicle;

    second means for producing a command signal indicative of a predetermined period of time defined by a desired speed of the vehicle;

    third means responsive to the timing signal for calculating a first time difference between the predetermined period of time and the actual period of time of the timing signal and for producing a first difference signal indicative of an absolute value of the calculated first time difference and a first sign signal indicative of the positive or negative sign of the calculated first time difference;

    fourth means responsive to the timing signal for calculating a second time difference between respective actual periods of time of the preceding and following timing signals and for producing a second difference signal indicative of an absolute value of the calculated second time differene and a second sign signal indicative of the positive or negative sign of the calculated second time difference;

    fifth means for limiting a value of the second difference signal to a predetermined maximum value when the actual acceleration of the vehicle exceeds a maximum value;

    sixth means responsive to the timing signal for calculating a sum of the absolute values when respective signs of the first and second sign signals are identical to each other and for calculating a difference between the absolute values when respective signs of the first and second sign signals are opposite to each other, said sixth means selectively producing first and second correction signals respectively indicative of the calculated sum and the calculated difference and ceasing to produce the first and second correction signals when the respective calculated values are zero;

    seventh means responsive to the timing signal and one of the first and second correction signals for selectively producing first and second control signals respectively in relation to the positive and negative signs of the second sign signal; and

    actuator means for decreasing and increasing the opening angle of said throttle valve respectively in response to the first and second control signals.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×