Vehicle Drive Control Apparatus Resolver Elimination
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Solution Overview
Problem
Existing vehicle drive systems rely on resolvers for detecting wheel speed and rotation angles, which can be costly and require a speed reducer, increasing complexity and cost.
Innovation Solution
A control apparatus that estimates the rotation angle of a rotating electrical machine using a wheel speed sensor, eliminating the need for a resolver and potentially reducing the speed reduction ratio, thereby simplifying the system and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a resolver is used to detect wheel speed and rotation angle, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the rotation angle detection function from the resolver and implements it through software estimation using wheel speed sensor data. The control apparatus estimates the rotation angle of the rotating electrical machine based on detection values from the wheel speed sensor, eliminating the need for the resolver's angle detection capability and reducing system complexity.
Solution Approach 2:
The wheel speed sensor is given a dual function: it not only detects wheel speed for vehicle control but also provides data for estimating the rotation angle of the rotating electrical machine. This multi-functionality eliminates the need for a separate resolver, reducing device complexity while maintaining measurement precision.
2Measurement precision
If a resolver is used for rotation angle detection, then measurement precision is improved, but cost increases
Solution Approach 1:
The patent replaces the expensive resolver with a cost-effective software-based estimation approach using data from the existing wheel speed sensor. This substitution significantly reduces manufacturing costs while providing sufficient rotation angle information for control purposes.
Solution Approach 2:
Instead of using a physical resolver to directly measure rotation angle, the system creates a computational model that estimates the rotation angle based on wheel speed data. This virtual copy of the angle information is sufficient for control applications and eliminates the need for expensive hardware.
3Force
If a speed reducer is used to obtain required output torque, then force output is improved, but device complexity increases
Solution Approach 1:
The patent replaces the mechanical speed reducer with an electrical torque control system. The control apparatus calculates the required output torque based on estimated rotation angle and wheel speed data, then directly controls the rotating electrical machine to produce the necessary torque, eliminating the need for mechanical transmission components.
Solution Approach 2:
The system changes from mechanical torque multiplication through a speed reducer to electrical torque control by adjusting the rotating electrical machine's operating parameters. This allows flexible torque control without mechanical transmission, reducing system complexity while maintaining force output capability.
Data Source
AI summary
A control apparatus is applied to a vehicle including (i) a rotating electrical machine and (ii) a wheel speed sensor detecting a wheel speed. The control apparatus sets a rotation angle of the rotating electrical machine based on an estimated value of the rotation angle which is estimated based on a detection value of the wheel speed sensor.