Automatic speed control system for automotive vehicles

An automatic speed control system for an automotive vehicle, comprising:

• detection means for detecting a vehicle speed of the vehicle;
• acceleration means for providing an increased acceleration exerted on the vehicle by automatically adjusting a driving force applied to road wheels;
• deceleration means for providing an increased deceleration exerted on the vehicle by automatically adjusting a braking force applied to the road wheels;
• first arithmetic means for calculating a value of a first command signal to be sent to said acceleration means, based on a target vehicle speed and the vehicle speed detected by said detection means;
• second arithmetic means for calculating a value of a second command signal to be sent to said deceleration means, based on said target vehicle speed and the vehicle speed detected by said detection means;
• and
• decision means for switching from one of a driving-force control of said acceleration means and a braking-force control of said deceleration means to another,
• wherein a first group of control gains used in said first arithmetic means and a second group of control gains used in said second arithmetic means are preset to provide transition durations in which said first command signal having a value greater than a first predetermined threshold and said second command signal having a value greater than a second predetermined threshold occur concurrently,
• wherein said decision means selectively outputs one of said first and second command signals to continue the corresponding one of said driving-force control and said braking-force control, executed prior to a transition, for each of said transition durations.

An automatic speed control system for an automotive vehicle, comprising:

• detection means for detecting a vehicle speed of the vehicle;
• acceleration means for providing an increased acceleration exerted on the vehicle by automatically adjusting a driving force applied to road wheels;
• deceleration means for providing an increased deceleration exerted on the vehicle by automatically adjusting a braking force applied to the road wheels;
• first arithmetic means for calculating a value of a first command signal to be sent to said acceleration means, based on a target vehicle speed and the vehicle speed detected by said detection means;
• second arithmetic means for calculating a value of a second command signal to be sent to said deceleration means, based on said target vehicle speed and the vehicle speed detected by said detection means;
• and
• decision means for switching from one of a driving-force control of said acceleration means and a braking-force control of said deceleration means to another,
• wherein a first group of control gains used in said first arithmetic means and a second group of control gains used in said second arithmetic means are preset to provide transition durations in which said first command signal having a value greater than a first predetermined threshold and said second command signal having a value greater than a second predetermined threshold occur concurrently,
• wherein said driving-force control is continued for said transition duration in which the value of said first command signal is decreasingly controlled toward said first predetermined threshold and then said driving-force control is switched to said braking-force control when said first predetermined threshold is reached, and said braking-force control is continued for said transition duration in which the value of said second command signal is decreasingly controlled toward said second predetermined threshold and then said braking-force control is switched to said driving-force control when said second predetermined threshold is reached.

An automatic speed control system for an automotive vehicle, comprising:

• detection means for detecting a vehicle speed of the vehicle;
• acceleration means for providing an increased acceleration exerted on the vehicle by automatically adjusting a driving force applied to road wheels;
• main deceleration means fluidly connected to a hydraulic brake system for providing an increased deceleration exerted on the vehicle by automatically adjusting a braking force applied to the road wheels;
• auxiliary deceleration means for producing an auxiliary braking force applied to the road wheels without utilizing the hydraulic brake system;
• first arithmetic means for calculating a value of a first command signal to be sent to said acceleration means, based on a target vehicle speed and the vehicle speed detected by said detection means;
• second arithmetic means for calculating a value of a second command signal to be sent to said main deceleration means, based on said target vehicle speed and the vehicle speed detected by said detection means;
• third arithmetic means for calculating a value of a third command signal to be sent to said auxiliary deceleration means, based on said target vehicle speed and the vehicle speed detected by said detection means;
• and
• decision means for switching from one of a driving-force control of said acceleration means and an auxiliary braking-force control of said auxiliary deceleration means to another, and for switching from one of said auxiliary braking-force control of said auxiliary deceleration means and a braking-force control of said main deceleration means to another, so that, during said driving-force control, said driving-force control is continued until the value of said first command signal reaches a first predetermined threshold and said driving-force control is switched to said auxiliary braking-force control when said first predetermined threshold is reached, and so that, during said auxiliary braking force control, said auxiliary braking-force control is continued until the value of said third command signal reaches one of the upper and lower predetermined thresholds and said auxiliary braking-force control is switched to said driving-force control when said upper predetermined threshold is reached and to said braking-force control when said lower predetermined threshold is reached, and so that, during said braking-force control, said braking-force control is continued until the value of said second command signal reaches a second predetermined threshold and said braking-force control is switched to said auxiliary braking-force control when said second predetermined threshold is reached, during a simultaneous occurrence of said first command signal having a value greater than said first predetermined threshold and said third command signal having a value greater than said lower predetermined threshold or during a simultaneous occurrence of said second command signal having a value greater than said second predetermined threshold and said third command signal having a value greater than said upper predetermined threshold.

An automatic speed control system for an automotive vehicle, comprising:

• detection means for detecting a vehicle speed of the vehicle;
• acceleration means for providing an increased acceleration exerted on the vehicle by automatically adjusting a driving force applied to road wheels;
• main deceleration means for providing an increased deceleration exerted on the vehicle by automatically adjusting a braking force applied to the road wheels;
• auxiliary deceleration means for producing an auxiliary braking force applied to the road wheels without utilizing the hydraulic brake system;
• first arithmetic means for calculating a value of a first command signal to be sent to said acceleration means, based on a target vehicle speed and the vehicle speed detected by said detection means;
• second arithmetic means for calculating a value of a second command signal to be sent to said main deceleration means, based on said target vehicle speed and the vehicle speed detected by said detection means;
• third arithmetic means for calculating a value of a third command signal to be sent to said auxiliary deceleration means, based on said target vehicle speed and the vehicle speed detected by said detection means;
• and
• decision means for switching from one of a driving-force control of said acceleration means and an auxiliary braking-force control of said auxiliary deceleration means to another, and for switching from one of said auxiliary braking-force control of said auxiliary deceleration means and a braking-force control of said main deceleration means to another;
• wherein a first group of control gains used in said first arithmetic means and a third group of control gains used in said third arithmetic means are preset to provide first transition durations between said driving-force control and said auxiliary braking-force control in which said first command signal having a value greater than a first predetermined threshold and said third command signal having a value greater than a lower predetermined threshold occur concurrently, and said third group of control gains used in said third arithmetic means and a second group of control gains used in said second arithmetic means are preset to provide second transition durations between said auxiliary braking-force control and said braking-force control in which said third command signal having a value greater than an upper predetermined threshold and said second command signal having a value greater than a second predetermined threshold occur concurrently,
• wherein said decision means selectively outputs one of said first, second and third command signals to continue the corresponding one of said driving-force control, said auxiliary driving-force control and said braking-force control, executed prior to a transition, for each of said first and second transition durations.

An automatic speed control system for an automotive vehicle, comprising:

• detection means for detecting a vehicle speed of the vehicle;
• acceleration means for providing an increased acceleration exerted on the vehicle by automatically adjusting a driving force applied to road wheels;
• main deceleration means for providing an increased deceleration exerted on the vehicle by automatically adjusting a braking force applied to the road wheels;
• auxiliary deceleration means for producing an auxiliary braking force applied to the road wheels without utilizing the hydraulic brake system;
• first arithmetic means for calculating a value of a first command signal to be sent to said acceleration means, based on a target vehicle speed and the vehicle speed detected by said detection means;
• second arithmetic means for calculating a value of a second command signal to be sent to said main deceleration means, based on said target vehicle speed and the vehicle speed detected by said detection means;
• third arithmetic means for calculating a value of a third command signal to be sent to said auxiliary deceleration means, based on said target vehicle speed and the vehicle speed detected by said detection means;
• and
• decision means for switching from one of a driving-force control of said acceleration means and an auxiliary braking-force control of said auxiliary deceleration means to another, and for switching from one of said auxiliary braking-force control of said auxiliary deceleration means and a braking-force control of said main deceleration means to another;
• wherein a first group of control gains used in said first arithmetic means and a third group of control gains used in said third arithmetic means are preset to provide first transition durations between said driving-force control and said auxiliary braking-force control in which said first command signal having a value greater than a first predetermined threshold and said third command signal having a value greater than a lower predetermined threshold occur concurrently, and said third group of control gains used in said third arithmetic means and a second group of control gains used in said second arithmetic means are preset to provide second transition durations between said auxiliary braking-force control and said braking-force control in which said third command signal having a value greater than an upper predetermined threshold and said second command signal having a value greater than a second predetermined threshold occur concurrently,
• wherein said driving-force control is continued for said first transition durations in which the value of said first command signal is decreasingly controlled toward said first predetermined threshold and then said driving-force control is switched to said auxiliary braking-force control when said first predetermined threshold is reached, and said auxiliary braking-force control is continued for said first transition durations in which the value of said third command signal is decreasingly controlled toward said lower predetermined threshold and then said auxiliary braking-force control is switched to said driving-force control when said lower predetermined threshold is reached, and
• wherein said auxiliary braking-force control is continued for said second transition durations in which the value of said third command signal is increasingly controlled toward said upper predetermined threshold and then said auxiliary braking-force control is switched to said braking-force control when said upper predetermined threshold is reached, and said braking-force control is continued for said second transition durations in which the value of said second command signal is decreasingly controlled toward said second predetermined threshold and then said braking-force control is switched to said auxiliary braking-force control when said second predetermined threshold is reached.