US 12,377,826 B2
Slope brake pressure determining method and determining system, and vehicle
Xianhui Zhang, Hefei (CN); Bohong Xiao, Hefei (CN); Shan Zou, Hefei (CN); and Da Yuan, Hefei (CN)
Assigned to NIO TECHNOLOGY (ANHUI) CO., LTD, Hefei (CN)
Filed by NIO TECHNOLOGY (ANHUI) CO., LTD, Hefei (CN)
Filed on Mar. 9, 2022, as Appl. No. 17/690,228.
Claims priority of application No. 202110265017.X (CN), filed on Mar. 11, 2021.
Prior Publication US 2022/0289153 A1, Sep. 15, 2022
Int. Cl. B60T 8/171 (2006.01); B60T 17/22 (2006.01)
CPC B60T 8/171 (2013.01) [B60T 17/221 (2013.01); B60T 2210/20 (2013.01); B60T 2220/04 (2013.01); B60T 2240/00 (2013.01); B60T 2250/00 (2013.01); B60T 2250/04 (2013.01); B60T 2270/88 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A slope brake pressure determining method, comprising:
a pre-braking slope determining step, in which a pre-braking slope estimated value is determined according to a specified cycle, wherein vehicle acceleration awheel is determined based on a current vehicle speed, a slope measured value ameasure is obtained based on a measured value of the vehicle acceleration, and a current pre-braking slope estimated value is determined based on the vehicle acceleration awheel and the slope measured value ameasure and is used as a first slope estimated value aestimate1, and wherein a pre-braking slope estimated value of a previous cycle that is latched prior to the establishment of brake pressure is used as a second slope estimated value aestimate2;
an in-braking slope determining step, in which an instantaneous vehicle speed vbrake prior to the establishment of the brake pressure is latched, a vehicle traveling distance lbrake and time tbrake are accumulated, and an in-braking slope estimated value aslop is determined based on the instantaneous vehicle speed vbrake prior to the establishment of the brake pressure and the vehicle traveling distance lbrake and time tbrake, wherein the instantaneous vehicle speed vbrake is an instantaneous vehicle speed when a brake is applied, and the vehicle traveling distance lbrake and time tbrake are a vehicle traveling distance and time that have been accumulated from a moment at which the brake is applied, wherein, in the pre-braking slope determining step, on a premise of identifying a braking condition, the pre-braking slope estimated value of the previous cycle, namely the second slope estimated value aestimate2, is latched prior to the establishment of the brake pressure, and wherein identifying the braking condition comprises identifying according to stop and deceleration commands from a vehicle brake switch or a vehicle main controller; and
a brake pressure determining step, in which pre-braking pressure p1 and in-braking pressure p2 are determined based on the second slope estimated value aestimate2 and a third slope estimated value aestimate3, respectively, initial brake pressure p3 is determined based on the pre-braking pressure p1 and the in-braking pressure p2, and final brake pressure p4 is determined based on the initial brake pressure p3, wherein the third slope estimated value aestimate3 is a slope estimated value determined using an observer.