US 12,227,156 B2
Vehicle brake control device and vehicle brake control method
Ryohei Tsugoshi, Tokyo (JP); Shumpei Onodera, Tokyo (JP); and Takuya Okahara, Tokyo (JP)
Assigned to Mitsubishi Electric Corporation, Tokyo (JP)
Appl. No. 17/255,482
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Jul. 25, 2018, PCT No. PCT/JP2018/027981
§ 371(c)(1), (2) Date Dec. 23, 2020,
PCT Pub. No. WO2020/021665, PCT Pub. Date Jan. 30, 2020.
Prior Publication US 2021/0146895 A1, May 20, 2021
Int. Cl. B60T 8/172 (2006.01); B60T 8/17 (2006.01); B60T 8/171 (2006.01); B60T 8/32 (2006.01); B60T 13/66 (2006.01); B60T 17/22 (2006.01); B61H 13/20 (2006.01)
CPC B60T 8/172 (2013.01) [B60T 8/1705 (2013.01); B60T 8/171 (2013.01); B60T 8/3235 (2013.01); B60T 13/662 (2013.01); B60T 17/221 (2013.01); B61H 13/20 (2013.01); B60T 2250/04 (2013.01); B60T 2270/88 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A vehicle brake control device to control a mechanical brake apparatus that comprises a brake cylinder and a friction member operating in accordance with a pressure of a fluid inside the brake cylinder and generates a braking force by pressing the friction member against a rotatable body that rotates when a vehicle travels, the vehicle brake control device comprising:
necessary braking force calculation processing circuitry to acquire a brake command indicating a target deceleration of the vehicle and calculate, based on the target deceleration indicated by the brake command, a necessary braking force that is the braking force necessary for obtaining the target deceleration;
initial speed acquisition processing circuitry to acquire a speed of the vehicle in response to the acquisition of the brake command by the necessary braking force calculation processing circuitry;
target pressing force calculation processing circuitry to calculate, using an average friction coefficient as a friction coefficient of a contact surface between the friction member and the rotatable body and from the average friction coefficient and the necessary braking force, a target pressing force that is a force for pressing the friction member against the rotatable body in order to obtain the necessary braking force, the average friction coefficient varying depending on (i) an initial speed that is the speed of the vehicle acquired by the initial speed acquisition processing circuitry and (ii) a pressing force that is a force for pressing the friction member against the rotatable body;
target pressure calculation processing circuitry to calculate a target pressure indicating a pressure of the fluid inside the brake cylinder that is necessary for obtaining the target pressing force; and
output processing circuitry to compress, in accordance with the target pressure, fluid supplied from a fluid source to supply the compressed fluid to the mechanical brake apparatus, wherein
the target pressing force calculation processing circuitry comprises:
an average friction coefficient calculation processing circuitry to calculate, from the average friction coefficient predetermined for each pressing force at each of predetermined speeds of the vehicle that are different from one another, the average friction coefficient for each pressing force at the initial speed; and
operation processing circuitry to calculate the target pressing force by (i) obtaining, from the average friction coefficient for each pressing force at the initial speed, a relational expression for calculating, using the average friction coefficient as a variable, the pressing force at the initial speed, (ii) obtaining, by regarding the necessary braking force as corresponding to a product of the average friction coefficient and the pressing force, an equation regarding the pressing force from the relational expression, and (iii) obtaining a solution of the equation.