Automatic speed control system for an automotive vehicle

An automatic speed control system for an automotive vehicle which adjusts the vehicle speed to a pre-set constant speed, comprising:

• a speed sensor which determines the vehicle speed and generates a sensor signal indicative of determined vehicle speed;
• a setting means operative at a desired vehicle speed which generates a reference signal indicative of a set speed of the vehicle;
• a control signal generator which compares said sensor signal and said reference signal to obtain the difference therebetween and which generates a control signal based on the determined difference;
• a control means operable to control an accelerator according to said control signal and which reduces the difference between the set speed and the actual speed;
• a second means connected for disabling said control signal and responsive to the deceleration of the vehicle to interrupt operation of the control system;
• a third means comprising a resume means, said third means connected for enabling said control signal and operable to return the control system to operative mode for returning the vehicle speed to said set speed, after the operation is interrupted by said second means;
• and
• a fourth means incorporated with said third means to prevent the control means from entering an operative condition thereof in response to the operative condition of said third means and to cause the control means to enter its operative condition in response to an subsequent inoperative condition of said third means,
• whereby erroneous operation of said control means due to a faulty resume means is prevented.

In an automatic speed control system for an automotive vehicle which adjusts the vehicle speed to a desired constant speed, which system includes a speed sensor for determining the vehicle speed and which generates a sensor signal corresponding to that speed, a control means determining the difference between the set speed and the actual vehicle speed and which generates a control signal responsive to which an adjusting means adjusts vehicle speed to reduce the difference between the set speed and the actual speed to zero, an interruption means for interrupting operation of the control system responsive to the application of the vehicle's brake and/or the disconnection of the vehicle's clutch and a restart means operable for generating a signal for returning the vehicle speed to said set speed after interrupting the control operation of the control system,

• a method for making the system fail-safe even when the restart means tends to induce failure of the system operation comprising the steps of:
• inhibiting operation of the adjusting means during the period of operation of said restart means;
• and
• activating the adjusting means upon determining that the restart means has returned to an inoperative condition,
• whereby erroneous operation of said adjusting means due to a faulty restart means is prevented.

An automatic cruise control system for an automotive vehicle comprising:

• a vehicle speed sensor for producing a vehicle speed signal representative of the vehicle speed;
• a preset speed signal generator means for producing a preset speed signal representative of the preset speed, said preset speed signal genertor means being variable for varying the preset speed as desired;
• a control means for comparing said vehicle speed signal value and said preset signal value to produce a control signal indicative of the difference therebetween, said control means feeding said control signal to an accelerator means of the vehicle for controlling the vehicle speed to said preset speed;
• a disable signal generator means for detecting a preselected disabling condition in the vehicle operation for disabling said control means as said predetermined disabling condition is detected;
• and
• a resume switch means adapted for resuming said cruise control and having an inoperative condition and an operative condition, for producing and maintaining a resume signal for resuming said cruise control operation, said resume signal maintained as long as said resume switch means is in its operative condition, which resume signal actuates said control means for resuming said cruise control operation when said resume switch means returns to its inoperative condition.

In an automatic cruise control system for an automotive vehicle for controlling a vehicle driving speed at a preset constant speed, and including a means for disabling cruise control when a preselected disabling condition is established, and a resume means having an inoperative condition and an operative condition for generating a resume signal to resume cruise control after termination of the disabling condition;

• a method for resuming the cruise control after said preselected disabling condition is terminated, comprising the steps of:
• detecting termination of said preselected disabling condition;
• producing a control signal depending upon a difference between said preset speed and a measured vehicle speed for controlling the vehicle driving speed at the preset constant speed;
• producing a resume signal for resuming cruise control, after the control is disabled by detection of the disabling condition;
• detecting an AND condition of said control signal and said resume signal for holding said control system in an inoperative condition as long as said AND condition is maintained;
• and
• resuming said cruise control in response to a return of the resume means to its inoperative condition and termination of said resume signal as detected by cessation of said AND condition.

In an automatic cruise control system for an automotive vehicle having an engine control section, a speed command section providing a speed difference signal to said engine control section, said speed difference signal representing a difference between a preset reference speed and actual vehicle speed, disabling means for disabling said engine control section and a restart means having an inoperative condition and an operative condition for generating a restart signal to resume operation of said engine control section subsequent to disabling thereof by said disabling means, the improvement comprising:

• means for delaying resumption of operation of said control system until termination of said restart signal generated by said restart means, including
• first means connected for receiving said difference signal,
• second means connected for receiving said restart signal, and
• third means, connected to said first and second means, for passing said speed difference signal to said engine control section for resuming operation of said engine control section only after said restart means has returned to an inoperative condition, after termination of said restart signal,
• whereby erroneous operation of said engine control section due to a faulty restart means is prevented.