MDPS Motor Angular Velocity Control for Steering Center Alignment
Solution Overview
Problem
Drivers experience inconvenience when attempting to center align the steering wheel after parking a vehicle equipped with motor-driven power steering (MDPS), leading to potential vehicle collisions due to lack of precise alignment.
Innovation Solution
A wheel alignment apparatus and control method that utilizes a motor-driven power steering system, detecting steering angles and aligning wheels with the center by controlling motor angular velocity and current, incorporating a request value generation unit, compensation value generation unit, steering position control unit, motor angular velocity control unit, motor current control unit, and switching unit to generate and adjust driving currents for precise alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional MDPS systems are used for steering control, then steering performance and manipulation force are improved, but center alignment precision after parking deteriorates due to lack of automatic alignment capability
Solution Approach 1:
The system enables automatic center alignment functionality where the MDPS motor autonomously returns the steering wheel to center position after parking without requiring manual driver intervention. The control unit detects parking state and automatically activates the alignment process, making the system self-serving for the alignment task.
Solution Approach 2:
The system employs steering angle sensors and motor angular velocity sensors to continuously monitor steering position and motor state. The control unit processes this feedback information to determine when center alignment is achieved and adjusts motor control accordingly, ensuring precise alignment through closed-loop feedback control.
2Device complexity
If manual center alignment is required after parking, then system complexity is reduced, but driver convenience and safety deteriorate due to inconvenient alignment process
Solution Approach 1:
The system automatically performs center alignment without requiring driver intervention. When parking is detected, the control unit autonomously activates the MDPS motor to return the steering wheel to center position, eliminating the need for manual alignment operations.
Solution Approach 2:
The system performs center alignment automatically at the moment of parking, before the driver needs to proceed with other operations. By detecting parking state and immediately initiating alignment, the system ensures center alignment is completed in advance, preventing potential collisions during subsequent maneuvers.
3Device complexity
If motor control is simplified without compensation mechanisms, then device complexity is reduced, but alignment precision deteriorates due to external disturbances like tire friction
Solution Approach 1:
The control unit receives feedback from motor angular velocity sensors and motor current sensors to monitor actual motor performance. Based on this feedback, the control unit adjusts control signals to compensate for external disturbances such as tire friction, ensuring precise alignment despite varying operating conditions.
Solution Approach 2:
The system dynamically adjusts motor control parameters including angular velocity and current based on detected operating conditions. The control unit modifies these parameters in real-time to compensate for external disturbances, maintaining alignment precision across different scenarios without requiring complex mechanical compensation mechanisms.
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
Enhances the precision of motor control for center alignment, minimizing the impact of external disturbances like tire friction and load, ensuring safe and accurate wheel alignment post-parking.
Implementation Method 1
a motor angular velocity sensor configured to detect a motor angular velocity of the MDPS motor
Implementation Method 2
a motor current sensor configured to detect a motor current of the MDPS motor
Implementation Method 3
the MDPS motor generates a power assist force through rotations and deceleration so as to rotate a universal joint
Data Source
AI summary
The present invention relates to a wheel alignment apparatus using a motor-driven power steering (MDPS) and a control method thereof. After a vehicle having the MDPS mounted therein is parked, a steering angle is detected and a wheel is aligned with the center by controlling an MDPS motor through a motor angular velocity and a motor current. Accordingly, the motor angular velocity of the MDPS motor which is actually driven to align the wheel with the center is controlled to improve the precision of motor control, regardless of external disturbance such as tire frictions or loads.