Steering Angle Sensor Dynamic Mode Control for Power Steering
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Solution Overview
Problem
Existing steering angle sensors for electrically driven power steering in motor vehicles face challenges in operating safely and efficiently, particularly in conserving energy when the vehicle is stationary to prevent battery discharge and ensuring accurate steering angle determination during power failures.
Innovation Solution
The steering angle sensor operates in multiple modes: continuous determination during vehicle operation, reduced energy consumption during brief stops, and standby mode with extended intervals, using a voltage sensor to adjust power usage and a backup capacitor for power failures, and switches between these modes based on vehicle state and supply voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the steering angle sensor continuously determines the steering angle during vehicle operation, then the steering angle detection accuracy is maintained, but the energy consumption increases
Solution Approach 1:
The patent implements dynamic operating modes that adapt the determination frequency of the steering angle to the current vehicle state. During vehicle operation, continuous determination maintains high accuracy, while during stationary periods, the system switches to reduced or standby modes with lower determination frequency, thereby reducing energy consumption while maintaining necessary measurement precision when needed
Solution Approach 2:
The system changes the operational parameters of the steering angle sensor based on vehicle state. By adjusting the determination frequency parameter - continuous during operation, reduced during brief stops, and standby during extended stationary periods - the system optimizes the balance between measurement accuracy and energy consumption
2Use of energy by moving object
If the steering angle sensor operates in standby mode with extended time intervals, then the energy consumption is reduced, but the response time for steering angle detection increases
Solution Approach 1:
The system performs preliminary actions by switching to reduced or standby modes only after detecting that the vehicle has been stationary for a predetermined period. This ensures that continuous operation mode is maintained during actual driving, while energy-saving modes are activated only when appropriate, preventing unnecessary delays in steering angle detection during operation
Solution Approach 2:
The patent implements periodic determination of the steering angle at extended time intervals during standby mode, rather than continuous determination. This periodic action significantly reduces energy consumption while still providing updated steering angle information at appropriate intervals during stationary periods
3Reliability
If separate energy stores are used to supply the processing unit during battery disconnection, then the zero position availability is ensured, but the device complexity increases
Solution Approach 1:
The patent employs a backup capacitor that is charged beforehand during normal operation to store electrical energy. In the event of battery disconnection or voltage failure, this pre-charged capacitor provides immediate power to maintain the determination of the zero position, ensuring reliability without requiring complex separate energy storage systems
Data Source
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AI summary
The sensor (3) has an input (19) for a rotor position signal of an electric motor of a power steering apparatus (1), where the sensor determines a steering angle of a steering wheel (16) based on the signal. The sensor continuously determines the steering angle during operation of a motor car and determines the steering angle in a set of preset time intervals during standstill of the car. The sensor determines the steering angle in another set of preset time intervals during short-time stopping of the car, where the latter set of time intervals is shorter than the former set of time intervals. Independent claims are also included for the following: (1) a control unit comprising a voltage converter (2) a method for operating an electrically driven power steering apparatus.