Electromechanical Power Steering Redundant Control Unit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromechanical power steering systems face challenges in maintaining stability and reliability due to the complexity and cost of redundant components, particularly in ensuring continued operation when sensors or control system parts fail.
Innovation Solution
The system incorporates a brushless DC motor with two winding sets, a main control unit, and intelligent driver control systems with microcontrollers, allowing for redundant control and communication between units to ensure continued operation even if one fails, with all components preferably arranged on a single printed circuit board for compactness and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If redundant control units with independent inverters and windings are used, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple control functions into a single integrated control unit that can operate in different modes (normal operation with both inverters, fault operation with one inverter). The control unit includes multiple microcontrollers that can work together or independently, merging what would traditionally be separate redundant control devices into one unified system that provides redundancy through software and control logic rather than complete hardware duplication.
Solution Approach 2:
The single control unit is designed to perform multiple functions: it can control both inverters simultaneously during normal operation, control a single inverter during fault conditions, and switch between different operational modes. The microcontrollers within the control unit can assume different roles depending on the system state, making the control unit universal and multi-functional rather than requiring dedicated redundant control devices.
2Reliability
If redundant control units with separate inverters are used, then reliability is improved, but manufacturing cost increases
Solution Approach 1:
The patent merges multiple control functions into a single control unit, reducing the total number of control devices that need to be manufactured and assembled. This integration approach lowers manufacturing costs while maintaining redundancy through intelligent control logic and multiple microcontrollers within the single unit.
Solution Approach 2:
Instead of duplicating entire control devices, the patent uses software-based redundancy where microcontrollers within the single control unit can replicate control functions. The control logic includes backup routines and fallback mechanisms that copy essential control capabilities without requiring separate physical control units.
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 design provides a simpler, cost-effective, and robust electromechanical power steering system with improved redundancy, ensuring reliable operation by enabling independent control tasks and data interchange between microcontrollers, thus maintaining steering assistance functions even in the event of component failures.
Implementation Method 1
an electric motor (5), having a stator (9), which is fitted with at least two electrical winding sets (18, 19), and having a rotor (8), which is fitted with permanent magnets, transforms electrical energy to mechanical energy
Data Source
AI summary
An electromechanical power steering system for a vehicle may include an electric motor having a stator fitted with at least two electrical winding sets and having a rotor fitted with permanent magnets. The electric motor may exert a steering movement introduced by a driver on the vehicle. A main control unit may determine a motor current prespecification based on the steering movement. The motor current prespecification can be output to the electrical winding sets and may comprise a power control unit that provides and feeds the motor current prespecification to the winding sets. A driver control system may be provided for each winding set, wherein all driver control systems and the main control unit each have a microcontroller and are combined to form an assembly. A power driver may be connected to each of the driver control systems, and at least two power drivers are arranged in a power control unit. Each power driver may be a half-bridge with power semiconductor switches.