Brake Torque Blending Control for Regenerative Deceleration Gaps
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Solution Overview
Problem
Conventional vehicle braking systems fail to adequately compensate for insufficient regeneration braking force, leading to a diminished braking feeling and reaction force, especially when the battery is fully charged, resulting in a shortfall in deceleration sensation.
Innovation Solution
A vehicle braking device that controls both hydraulic and regeneration brake systems based on acceleration and brake values, utilizing dividers and a controller to optimize braking force distribution between the two systems, ensuring improved braking sensation by adjusting torque demands and managing torque distribution between the hydraulic and regeneration brake systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If regeneration braking force is increased to improve energy recovery, then battery charging efficiency is improved, but when battery is fully charged the regeneration braking force becomes insufficient leading to deterioration of brake operating feeling
Solution Approach 1:
The control device dynamically adjusts the distribution ratio between regeneration braking force and friction braking force based on battery charge state. When battery charge level is high, the system increases the proportion of friction braking force to maintain adequate total braking force, ensuring brake operating feeling remains satisfactory while still utilizing available regeneration braking capacity
Solution Approach 2:
The braking system transitions from a static braking force distribution to a dynamic one that adapts in real-time to battery charge state. The control device continuously monitors battery charge level and adjusts the mixing ratio of regeneration and friction braking forces, creating a flexible system that optimizes both energy recovery and brake feeling under varying conditions
2Force
If friction braking force is increased to compensate for insufficient regeneration braking force, then deceleration performance is maintained, but brake operating feeling deteriorates due to mismatch between driver expectation and actual braking force
Solution Approach 1:
The control device incorporates feedback from the brake pedal operation amount to dynamically adjust the distribution of braking forces. By monitoring how much the driver presses the brake pedal, the system calculates the appropriate friction braking force to apply while compensating for insufficient regeneration braking force, ensuring the total braking force matches driver expectations and maintains natural brake operating feeling
Data Source
AI summary
The disclosed vehicle braking device controls a hydraulic brake system (2) and a regeneration brake system (3) mounted on a vehicle (1) in accordance with an acceleration value and a brake value, and includes a first divider (11), a second divider (12), and a controller (13). The first divider (11) divides a driver demand torque set according to the accelerator value into a target coast torque and a remaining torque. The second divider (12) divides a sum of a deceleration torque set according to the brake value and the target coast torque divided by the first divider (11) into a hydraulic-brake demand torque and a regeneration-brake demand torque. The controller (13) controls the hydraulic brake system (2), using the hydraulic-brake demand torque, and controls the regeneration brake system (3), using a total regeneration brake torque calculated from the remaining torque and the regeneration-brake demand torque. This configuration can improve the feeling of operating the brake, resolving the feeling of the shortage of deceleration.