Steering Angle Detection Using Motor Magnetic Properties
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Solution Overview
Problem
Existing steering arrangements lack precise and reliable measurement of the steering angle, leading to potential position drift without physical movement.
Innovation Solution
A steering arrangement utilizing a multipole-motor with integrated sensor output, where the motor is used to provide angular position information without activation, and combined with an angle sensor and motor controllers for redundancy, allowing precise angle detection and force feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If integration of speed signal is used to obtain position, then position information can be obtained, but position drift occurs even without physical movement
Solution Approach 1:
The patent implements feedback by continuously monitoring the relationship between speed signals and position changes. The controller detects discrepancies between integrated position and actual physical position, then applies correction algorithms to eliminate drift accumulation, ensuring long-term position accuracy.
Solution Approach 2:
The system uses its own motor components to generate position information without requiring separate sensors. The motor's back-EMF and current characteristics provide self-contained position data, and the system automatically compensates for integration drift using its control algorithms.
2Measurement precision
If separate angle sensor is added for precise measurement, then position accuracy improves, but device complexity and space requirements increase
Solution Approach 1:
The motor serves multiple functions: it provides both the driving force for the steering mechanism and generates position information through its electrical characteristics. The same motor windings that produce torque also generate back-EMF signals that encode position data, eliminating the need for dedicated angle sensors.
Solution Approach 2:
The patent merges the functions of the motor and angle sensor into a single integrated system. The motor's electrical parameters (current, voltage, back-EMF) are used directly for position detection, combining actuation and sensing functions into one component rather than using separate devices.
3Force
If motor is activated for control purposes, then steering force is provided, but position measurement accuracy decreases due to feedback force generation
Solution Approach 1:
The patent segments the motor control into distinct operational modes: a measurement mode where the motor is deactivated for high-precision position detection, and a control mode where the motor is activated for providing steering assistance. This temporal separation allows both functions to operate at optimal performance levels.
Solution Approach 2:
The system dynamically switches between measurement and control states based on operational requirements. During measurement phases, the motor is deactivated to eliminate feedback forces and achieve maximum position accuracy. During control phases, the motor is activated to provide the necessary steering force, with position measurement resuming in between updates.
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 angular position resolution and redundancy, ensuring precise and reliable steering angle measurement with functional safety and force feedback without additional space requirements.
Implementation Method 1
When the steering command device is actuated the motor is operated as generator and produces a voltage which is proportional to a speed of the rotor of the motor
Data Source
Figure 1~2
AI summary
A steering arrangement comprising a housing (4), a steering command device (1) and an angle detector comprising an electrical motor (11) having motor windings (7) and motor controller means is disclosed, wherein the rotor of the motor (11) is in operative connection with the steering command device (1) and can be operated as generator. In such a steering arrangement the absolute angle of the steering command device should be obtained in a simple way. To this end the motor controller means derive an angle signal from magnetic properties of the electric motor (11).