Electric Vehicle Active Safety Control via Motor Torque Distribution
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Solution Overview
Problem
The existing hydraulic electronic stability control systems in electric vehicles are complex, costly, and have slow response speeds, leading to suboptimal operational stability and safety due to limitations in regenerative braking force and yaw control capabilities.
Innovation Solution
An active safety control system for electric vehicles that includes multiple wheels, motors, wheel speed detection, steering wheel rotation angle sensors, and a battery pack, which uses a motor controller to implement driving force and braking force yaw control modes to improve stability and safety by dynamically adjusting torque distribution across wheels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydraulic braking system is used for ESP control, then reliable vehicle stability control is achieved, but the system becomes complex, costly, and slow to respond
Solution Approach 1:
The patent replaces the hydraulic braking system with an electric braking system using hub motors. The motor controller delivers braking torque to individual wheels through electric motor control, eliminating the need for hydraulic pumps, valves, and brake calipers while achieving the same vehicle stability control function. This substitution reduces mechanical complexity and improves response speed.
Solution Approach 2:
The hub motor serves multiple functions: it acts as both a drive motor for propulsion and a brake for stopping and stability control. By integrating these functions into a single component, the system eliminates separate hydraulic braking mechanisms, reducing overall system complexity while maintaining reliable vehicle control.
2Loss of energy
If regenerative braking is used in hub motors, then energy recovery is achieved, but insufficient braking force is generated for effective yaw control
Solution Approach 1:
The patent changes the operating parameters of the hub motor to optimize braking force generation. By controlling the motor to operate in a high-torque regime during braking, the system generates sufficient braking force for effective yaw control while still recovering energy. The motor controller adjusts current and voltage parameters to maximize braking capability when needed.
Solution Approach 2:
The system alternates between regenerative braking mode and friction braking mode depending on the braking force requirements. During mild braking situations, regenerative braking recovers energy; during heavy braking or stability control situations, friction braking provides the necessary force. This periodic switching optimizes both energy recovery and braking performance.
3Device complexity
If only braking force is used for yaw control, then system simplicity is maintained, but operational stability is insufficient
Solution Approach 1:
The patent implements dynamic control by allowing the hub motors to operate in both driving and braking modes based on real-time vehicle stability requirements. The motor controller continuously adjusts the torque direction and magnitude on each wheel, enabling the system to provide both driving force and braking force as needed for optimal vehicle stability control.
Solution Approach 2:
The system uses feedback from sensors monitoring vehicle motion parameters to dynamically adjust motor torque output. Based on this feedback, the controller determines whether driving force or braking force is needed on each wheel to maintain vehicle stability, enabling adaptive control that improves operational stability while maintaining system simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system enhances operational stability and safety by enabling rapid correction of vehicle attitude and improving turning speed, reducing the impact of braking, and facilitating a stable state through advanced torque control, thus addressing the limitations of existing systems.
Implementation Method 1
multiple motors that are respectively connected to the multiple transmissions to respectively correspond to the multiple wheels
Data Source
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AI summary
The present invention discloses an electric vehicle, an active safety control system of an electric vehicle, and a control method of the active safety control system of an electric vehicle. The electric vehicle includes: multiple wheels, multiple motors respectively corresponding to the multiple wheels, a wheel speed detection module that generates a wheel speed signal, a steering wheel rotation angle sensor that detects direction information of the electric vehicle, a yaw rate sensor that detects yaw information of the electric vehicle, and a battery pack. The active safety control system includes: an acquisition module, acquiring the wheel speed signal, the direction information of the electric vehicle, the yaw information of the electric vehicle, status information of the battery pack, and status information of the multiple motors; a status determining module, determining status of the electric vehicle; and a control module, generating a control instruction and delivering the control instruction to at least one motor, so that when the electric vehicle has a side slip and is about to enter a side slip limit interval, the at least one motor is enabled to perform driving control on at least one corresponding wheel; and when the electric vehicle is in the side slip limit interval, the at least one motor is enabled to perform braking control on the at least one corresponding wheel.