US 12,447,942 B2
Method for testing the functional capability of a hydraulic vehicle braking system
Carsten Thierer, Abstatt (DE); Rolf-Hermann Mergenthaler, Leonberg (DE); Otmar Bussmann, Abstatt (DE); Peter Ziegler, Grossbottwar (DE); and Tim-Philipp Jesse, Sachsenheim (DE)
Assigned to ROBERT BOSCH GMBH, Stuttgart (DE)
Appl. No. 17/259,160
Filed by Robert Bosch GmbH, Stuttgart (DE)
PCT Filed May 25, 2019, PCT No. PCT/EP2019/063555
§ 371(c)(1), (2) Date Jan. 9, 2021,
PCT Pub. No. WO2020/025188, PCT Pub. Date Feb. 6, 2020.
Claims priority of application No. 102018212850.2 (DE), filed on Aug. 1, 2018.
Prior Publication US 2021/0316709 A1, Oct. 14, 2021
Int. Cl. B60T 17/22 (2006.01); B60T 8/40 (2006.01); B60T 13/14 (2006.01); B60T 13/68 (2006.01)
CPC B60T 17/221 (2013.01) [B60T 8/4081 (2013.01); B60T 13/142 (2013.01); B60T 13/148 (2013.01); B60T 13/686 (2013.01); B60T 2270/406 (2013.01)] 25 Claims
OG exemplary drawing
 
1. A method for testing the functional capability of a hydraulic vehicle braking system, the vehicle braking system including a master brake cylinder and a power brake pressure generator, to which jointly at least one hydraulic wheel brake is connected, and a separating valve that is in a line of a brake and is assigned to the master brake cylinder using which the master brake cylinder is hydraulically disconnectable from the power brake pressure generator and the at least one wheel brake, the method comprising the following steps:
switching the power brake pressure generator on when the master brake cylinder is not actuated; and
after the switching on, measuring and assessing a pressure in the vehicle braking system and/or a movement of the power brake pressure generator;
wherein the method includes at least one of the following features:
(a) testing whether the separating valve is malfunctioning to be in a closed position by executing an algorithm that is configured to cause performance of the following in a testing period:
(i) performing a control to place the separating valve in an open position during an open-valve-position period;
(ii) during the open-valve-position period, performing the switching of the power brake pressure generator to displace brake fluid onto the line of the brake circuit; and
(iii) identifying that the separating valve is malfunctioning to be in the closed position based on, while the displacement is occurring, a detection of a rotation of the motor being below a predefined rotation rate or slowing;
(b) testing whether the separating valve is malfunctioning to be in the open position by executing an algorithm that is configured to cause performance of the following in the testing period:
(i) performing a control to place the separating valve in the closed position during a closed-valve-position period;
(ii) during the closed-valve-position period, performing the switching of the power brake pressure generator to displace brake fluid onto the line of the brake circuit; and
(iii) identifying that the separating valve is malfunctioning to be in the open position based on, while the displacement is occurring, a detection of a lack of a slowing of a rotation of the motor;
(c) testing whether a simulator valve, by which a pedal travel simulator is connected to the master brake cylinder, is malfunctioning by executing an algorithm that is configured to cause performance of the following in the testing period:
(i) performing a control to place the simulator valve in a closed position during a closed-simulator-valve-position period;
(ii) during the closed-simulator-valve-position period, performing the switching of the power brake pressure generator to displace brake fluid onto the line of the brake circuit; and
(iii) identifying that the simulator valve is malfunctioning based on, while the displacement is occurring, at least one of:
a detection of a delay of a deceleration of at least one of a piston and the motor of the power brake pressure generator; and
a detection of a pressure build up on the brake circuit occurring with a delay;
(d) testing whether a reservoir valve between a brake fluid reservoir and the brake circuit is malfunctioning by executing an algorithm that is configured to cause performance of the following in the testing period:
(i) performing a control to place the reservoir valve in a closed position during a closed-reservoir-valve-position period;
(ii) during the closed-reservoir-valve-position period, performing the switching of the power brake pressure generator to displace brake fluid onto the line of the brake circuit; and
(iii) identifying that the reservoir valve is malfunctioning based on, while the displacement is occurring, a detection of a lack of the deceleration of the at least one of the piston and the motor of the power brake pressure generator; and
(e) testing a suctioning function of the power brake pressure generator by executing an algorithm that is configured to cause performance of the following in the testing period:
(i) performing the switching of the power brake pressure generator to displace brake fluid onto the line of the brake circuit by shifting the piston in a pressure-generating direction during a fluid displacement period;
(ii) upon conclusion of the fluid displacement period, closing a power valve thereby disconnecting the power brake pressure generator from the line of the brake circuit;
(iii) while the power valve is in a closed state due to the closing of the power valve, performing a control to shift the piston opposite to the pressure-generating direction; and
(iv) identifying the suctioning function is malfunctioning based on at least one of:
a detection of a decrease of pressure in a cylinder in which the piston is shifted;
a detection of a deceleration of a movement of the piston;
a detection of a deceleration of the motor.