Mitsubishi Motors has been granted a patent for a vehicle braking device that improves the feeling of operating the brake and resolves the issue of deceleration shortage. The device controls a hydraulic brake system and a regeneration brake system based on acceleration and brake values, dividing the driver demand torque and controlling the brake systems accordingly. GlobalData’s report on Mitsubishi Motors gives a 360-degree view of the company including its patenting strategy. Buy the report here.
According to GlobalData’s company profile on Mitsubishi Motors, HEV energy management was a key innovation area identified from patents. Mitsubishi Motors's grant share as of September 2023 was 30%. Grant share is based on the ratio of number of grants to total number of patents.
A braking device for controlling hydraulic and regeneration brakes
A recently granted patent (Publication Number: US11760204B2) describes a vehicle braking device that controls both a hydraulic brake system and a regeneration brake system based on acceleration and brake values. The device includes a first divider that divides the driver demand torque into a target coast torque and a remaining torque. The target coast torque is applied to the hydraulic brake system, while the remaining torque is used for further calculations.
A second divider then divides the sum of the deceleration torque and the target coast torque into a hydraulic-brake demand torque and a regeneration-brake demand torque. A controller is responsible for controlling the hydraulic brake system using the hydraulic-brake demand torque and the regeneration brake system using a total regeneration brake torque.
The patent also includes several additional claims. Claim 2 states that the target coast torque is set to the larger absolute value between a predetermined limit value and the driver demand torque. Claim 3 specifies that the predetermined limit value corresponds to an engine brake torque. Additionally, claim 4 states that the predetermined limit value decreases as the vehicle speed decreases.
The controller is further responsible for calculating the engine generation electric power by adding the total regeneration brake torque to the larger of the driver demand torque and the remaining torque, as stated in claims 5, 6, 10, 11, 13, 14, 16, and 17.
Claims 7 and 12 introduce the concept of a regeneration limit torque, which includes an engine friction torque and a torque determined by multiplying a coefficient with a value obtained by dividing the sum of various electric powers by the vehicle speed. The predetermined limit value is set to be smaller as the vehicle speed decreases, as stated in claims 8, 9, 12, 13, 15, and 16.
Overall, this patent describes a vehicle braking device that effectively controls both hydraulic and regeneration brake systems based on acceleration and brake values. The device optimizes the distribution of torque and calculates engine generation electric power to enhance the overall braking performance of the vehicle.