Brake control system for vehicle

A system for controlling a brake of a vehicle, comprising:

• braking pressure adjusting means for adjusting a braking pressure transferred through a hydraulic pressure system to a braking device for braking a wheel of said vehicle;
• wheel speed detecting means for detecting a wheel speed of said wheel;
• vehicle speed detecting means for detecting a speed of said vehicle;
• and
• control means for determining a target wheel speed on the basis of the detected vehicle speed and for controlling said braking pressure adjusting means using a feedback control so that the detected wheel speed is equal to the determined target wheel speed, said control means having state variable determining means for determining state variables representing the internal state of a system performing the brake of said wheel including a variable corresponding to a dead time on control of said hydraulic pressure system, and said control means including integral-added optimal regulator means for acquiring an optimal feedback gain in accordance with a dynamic model of a system for performing braking of said wheel and for performing said feedback control by determining a control amount for said braking pressure adjusting means on the basis of the detected wheel speed, the determined target wheel speed, the determined state variables, and said optimal feedback gain.

A system for controlling a brake of a vehicle, comprising:

• braking pressure adjusting means for adjusting a braking pressure transferred through a hydraulic pressure system to a braking device, for braking a wheel of said vehicle;
• slip ratio detecting means for detecting a slip ratio of said wheel of said vehicle;
• target slip ratio setting means for setting a slip ratio of said wheel so as to maximize a friction force between said wheel and a road surface;
• and
• brake controlling means for controlling said braking pressure adjusting means using a feedback control so that the detected slip ratio of said wheel becomes equal to the set target slip ratio, said brake controlling means including state variable determining means for determining state variables representing an internal state of a system performing the braking of said wheel including a variable corresponding to a dead time on control of said hydraulic pressure system, and said brake controlling means including an integral-added optimal regulator means for acquiring an optimal feedback gain in accordance with a dynamic model of a system performing the braking of said wheel and for performing the feedback control by determining a control amount for said braking pressure adjusting means on the basis of the detected slip ratio, the determined state variables, and said optimal feedback gain.

A system for controlling a brake of a vehicle comprising:

• rotational speed detecting means for detecting a rotational speed of a wheel of said vehicle;
• target rotational speed setting means for setting a target rotational speed for said wheel;
• braking pressure adjusting means for adjusting a braking pressure supplied to a braking device for braking said wheel, in accordance with a drive signal;
• and
• brake control means for controlling said braking pressure adjusting means so that the detected rotational speed of said wheel becomes equal to the target rotational speed set by said target rotational speed setting means, said brake control means including:
• (a) state observer means for determining parameters determined in accordance with a dynamic model of the system which is predetermined through system identification, for estimating state variable of an appropriate order indicative of a dynamic internal state of the system, and for performing brake control of said vehicle on the basis of the wheel rotational speed detected by the rotational speed detecting means, the previous braking pressure of said braking device determined by said brake control means, and said determined parameters;
• accumulatng means for obtaining a deviation of the rotational speed detected by said wheel rotational speed detecting means from said target rotational speed set by said target rotational speed setting means and for calculating an integrated value of the obtained deviation;
• braking pressure determining means for obtaining a predetermined optimal feed back gain, predetermined in accordance with said dynamic model and for obtaining a braking pressure to be supplied to said braking device on the basis of the estimated state variables, the calculated integrated value, and said optimal feedback gain and for generating a control signal indicative of the obtained braking pressure;
• and
• drive signal generating means resposive to the control signal from said braking pressure determining means for generating said drive signal and supplying the generated drive signal to said braking pressure adjusting means.

A system for controlling a brake of a vehicle, comprising:

• braking pressure adjusting means for adjusting a braking pressure supplied to a braking device for braking a wheel of said vehicle, the braking pressure based on a braking operation of a vehicle driver and being adjusted in accordance with a pressure control signal;
• slip ratio detecting means for detecting a slip ratio of said wheel;
• and
• brake control means for generating said pressure control signal to control said braking pressure adjusting means so that the detected slip ratio becomes equal to a target slip ratio, said brake control means comprising:
• (a) state observer means for estimating state variables indicative of an internal state of the brake control system, the state variables including a variable representing at least the control dead time of said braking pressure adjusting means;
• (b) accumulating means for accumulating a deviation between the target slip ratio and the detected slip ratio;
• (c) control amount determined means for determining a control amount on the basis of an optimal feedback gain determined in advance in accordance with a dynamic model of the system which is predetermined through system identification, the state variable estimated by said state observer means, the accumulated value obtained by the accumulating means, and the slip ratio detected by the slip ratio detecting means;
• and
• (d) pressure control signal generating means for generating said pressure control signal on the basis of the determined control amount and for supplying it to said braking pressure adjusting means.

A system for controlling a brake of a vehicle, comprising:

• braking pressure adjusting means for adjusting a braking pressure supplied to a braking device for braking a wheel of said vehicle, the braking pressure being based on a braking operation of a vehicle driver and being adjusted in accordance with a pressure control signal;
• rotational angular velocity detecting means for detecting a rotational angular velocity of said wheel;
• vehicle speed detecting means for detecting a speed of said vehicle;
• and
• brake control means for calculating a target rotational angular velocity on the basis of the detected vehicle speed and for controlling said braking pressure adjusting means so that the detected rotational angular velocity vecomes equal to the calculated target rotational angular velocity, said brake control means including:
• (a) state observer means for estimating state variables indicative of an internal state of the brake control system, the state variables including a variable representing at least the control dead time of said braking pressure adjusting means;
• (b) accumulating means for integrating a deviation between the target rotational angular velocity and the detected rotational angular velocity;
• (c) control amount determining means for determining a control amount on the basis of a optimal feedback gain determined in advance in accordance with a dynamic model of the system which is predetermined through system identification, the state variables estimated by said state observer means, the value obtained by the accumulating means, the calculated target rotational angular velocity, and the detected rotational angular velocity;
• and
• (d) pressure control signal generating means for generating said pressure control signal on the basis of the determined control amount and for supplying it to said braking pressure adjusting means.