Vehicular Transfer Control Device Current Feedback
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Solution Overview
Problem
The control processing load for vehicular transfer systems is high due to the need for precise detection of shaft angle variations, which can lead to reduced responsiveness and durability if the motor angle sensor is not used or if the differential term is not calculated, causing potential overshooting and hunting of the target angle.
Innovation Solution
A control device that calculates a holding current as a target current to maintain the torque distribution ratio using current feedback control, eliminating the need for position feedback control and reducing the control processing load by using a driver circuit, current sensor, and control circuit to adjust the electric motor's operation amount.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If position feedback control using motor angle sensor is used to calculate differential term in PID control, then the precision of differential term calculation is improved, but the control processing load increases
Solution Approach 1:
The invention extracts the essential control function from position-based PID control to current-based control. Instead of using motor angle sensor and calculating differential term of position, the system directly controls motor current to achieve the desired torque distribution ratio, eliminating the need for complex position feedback processing while maintaining control effectiveness
Solution Approach 2:
The invention replaces the mechanical/position-based feedback control system with an electrical/current-based control system. By substituting position feedback (requiring angle sensor and complex calculations) with direct current control, the system achieves the same control objective with reduced processing complexity
2Device complexity
If motor angle sensor is not used or differential term is not calculated to reduce control processing load, then the control processing load is reduced, but the shaft angle may overshoot target angle and responsiveness is reduced
Solution Approach 1:
The invention implements current feedback control where the actual motor current is measured and fed back to the control unit. This feedback mechanism allows the system to dynamically adjust the driving force based on actual conditions, preventing overshooting and maintaining responsiveness without requiring complex position-based differential control
Solution Approach 2:
The invention changes the control parameter from position (shaft angle) to current (motor output force). By controlling the motor current directly rather than positioning the shaft, the system achieves faster and more direct control response, improving responsiveness while reducing processing complexity
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
This approach reduces the control processing load while maintaining responsiveness and durability by using current feedback control to adjust the electric motor's operation, thereby suppressing reductions in the transfer's responsiveness and durability.
Implementation Method 1
a current sensor that detects an actual current of the electric motor
Implementation Method 2
a driver circuit that drives the electric motor
Implementation Method 3
performs current feedback control by calculating an operation amount of the electric motor so as to adjust the actual current to the target current
Data Source
AI summary
A transfer (13) that changes a distribution ratio of torque to be transmitted to a wheel using an electric motor (43), is controlled by a TF-ECU (18). The TF-ECU (18) includes a driver circuit (200) that drives the electric motor (43), a current sensor (53) that detects an actual current of the electric motor (43), and a microcomputer (100) that calculates a target current (I*) corresponding to a desired distribution ratio of torque and performs current feedback control for calculating an operation amount (D) of the electric motor (43) so as to adjust an actual current (Ia) to the target current (I*), and then outputs to the driver circuit (200) a drive signal corresponding to the operation amount (D).