METHOD FOR DETERMINING A CONTROL SIGNAL FOR AN ELECTRONICALLY CONTROLLABLE PRESSURE MEDIUM CONTROL VALVE OF AN ELECTRONICALLY SLIP-CONTROLLABLE POWER BRAKING SYSTEM

• US 20190315328A1
• Filed: 04/10/2019
• Published: 10/17/2019
• Est. Priority Date: 04/12/2018
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Gardt, Andrej, Eisele, Christoph, Schubitschew, Valentin, Edelmann, Volker
• Granted Patent: US 10,882,502 B2
• Time in Patent Office: Days
• CPC Class Codes: B60T 13/146 Part of the system directly actuated by booster pressure
• CPC Class Codes: B60T 13/662 characterised by specified functions of the control system components
• CPC Class Codes: B60T 13/68 by electrically-controlled valves B60T13/662 and B60T13/665 take precedence
• CPC Class Codes: B60T 13/686 in hydraulic systems or parts thereof
• CPC Class Codes: B60T 13/745 acting on a hydraulic system, e.g. a master cylinder
• CPC Class Codes: B60T 15/36 Other control devices or valves characterised by definite functions electrically controlled valves in fluid-pressure brake systems B60T15/027, B60T15/028
• CPC Class Codes: B60T 2201/12 Pre-actuation of braking systems without significant braking effect; Optimizing brake performance by reduction of play between brake pads and brake disc
• CPC Class Codes: B60T 7/042 by electrical means, e.g. using travel or force sensors
• CPC Class Codes: F16D 65/28 arranged apart from the brake

Abstract

A method is described for determining a control signal for a controllable pressure medium control valve of an electronically slip-controllable power braking system. The underlying power braking system is equipped with an actuating unit including a displaceable actuating element, the displacement of the actuating element determining a throughput of pressure medium through the pressure medium control valve. In the opened state, the pressure medium flowing through the pressure medium control valve causes flow forces on a valve closing element. Under certain circumstances, these flow forces have a closing effect on the valve closing element, thus throttling the possible pressure medium throughput, and cause undesirably high pressure differences in the interior of the pressure medium control valve. To avoid these effects, it is provided that the pressure medium control valve be controlled using a control signal dependent on the speed of an actuation of the actuating element.

Claims

1. A method for determining a control signal for an electronically controllable pressure medium control valve of an electronically slip-controllable power braking system, comprising:

actuating the power braking system being with the aid of a displaceable actuating element;

detecting, by a sensor unit, an actuating travel of the actuating element over time, wherein the sensor unit forwards the actuating travel to an electronic control unit for brake pressure control of the power braking system;

ascertaining, by the electronic control unit, a speed at which the actuating element is displaced; and

controlling the pressure medium control valve by the electronic control unit using a first control signal that is dependent on the ascertained speed of the actuating element.

2. The method as recited in claim 1, wherein:

the actuating travel extends between a starting position and a variably settable actuation position of the actuating element,

a second control signal that is independent of the speed of the actuating element is output to the pressure medium control valve in response to the actuating element moving from the starting position in a direction of the actuation position, and

the first control signal dependent on the speed is output to the pressure medium control valve in response to the actuating element moving from the actuation position back in the direction of the starting position.

3. The method as recited in claim 1, further comprising:

outputting, by the electronic control unit, a third control signal adapted to the speed of the actuating element to the pressure medium control valve in response to the ascertained speed of the actuating element exceeding a threshold value stored in the electronic control unit.

4. The method as recited in claim 1, wherein an increase in the third control signal is output to the pressure medium control valve by the electronic control unit with increasing speed of the actuating element.

5. The method as recited in claim 1, wherein a current strength by which the pressure medium control valve is controlled by the electronic control unit is used as the first control signal.

6. The method as recited in claim 1, further comprising:

controlling a pressure medium connection of an actuatable master brake cylinder to a pedal travel simulator of the power braking system using the pressure medium control valve.

7. The method as recited in claim 1, further comprising:

actuating a valve closing element of the pressure medium control valve, the pressure medium control valve having a bidirectional flow-through, wherein;

the valve closing element is switchable from a basic position in which the pressure medium control valve is impenetrable by a pressure medium into another switch position in which the pressure medium control valve is penetrable by the pressure medium.