Power Steering Torque Control via Path-Dependent Setpoint
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of conventional steering wheel assist functions and automatic piloting functions in vehicles often leads to conflicts, resulting in deteriorated performance and safety issues due to opposing actions, and instability during transitions between manual and autonomous steering control.
Innovation Solution
A method for managing power steering that involves measuring the driver's torque and comparing it to a setpoint, while also assessing vehicle path deviations to adjust the assist motor torque, allowing the automatic piloting function to define a driver torque setpoint that complements the maneuver assist function, thereby preventing direct interference and ensuring stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If automatic piloting functions and maneuver assist functions act simultaneously with各自 setpoints, then both functions can operate independently, but the systematic averaging of opposing contributions deteriorates individual function performances
Solution Approach 1:
The patent introduces an intermediary variable (driver torque setpoint) that translates the path control objectives into torque commands. Instead of directly summing opposing motor torque setpoints from automatic piloting and maneuver assist functions, the system uses the driver torque setpoint as a mediator to coordinate both functions, allowing them to operate simultaneously without direct conflict while maintaining individual performance integrity.
2Measurement precision
If automatic piloting function actively controls steering to follow reference path, then path following accuracy improves, but it opposes manual steering maneuvers and creates safety issues
Solution Approach 1:
The patent implements feedback mechanisms where the driver torque setpoint is continuously adjusted based on path deviation measurements. The automatic piloting function monitors the vehicle's position relative to the reference path and dynamically modifies the driver torque setpoint to guide the vehicle back toward the desired path, creating a coordinated response that maintains path following accuracy while avoiding harmful opposing actions through adaptive feedback control.
3Adaptability or versatility
If transitions between automatic piloting and manual maneuver assist are enabled, then system adaptability improves, but instabilities are generated that affect maneuver comfort and vehicle safety
Solution Approach 1:
The patent employs dynamic adjustment of the driver torque setpoint during transitions between automatic piloting and manual maneuver assist modes. The system continuously adapts the torque commands based on the current operating state and transition phase, ensuring smooth and stable control characteristics throughout mode changes. This dynamic approach maintains steering control stability while preserving the flexibility to switch between different control modes as needed.
Data Source
AI summary
A method for managing a power steering system including at least one steering wheel and at least one assist motor, the method including a step of driver torque control, which involves evaluating a driver torque difference that corresponds to the difference between a predefined driver torque setpoint and the actual driver torque actually exerted by the driver on the steering wheel, then determining an engine torque setpoint for torque applied to the assist motor in order to reduce the driver torque difference, the driver torque setpoint being generated during a trajectory control step, which involves evaluating a trajectory difference, for example a position difference, which corresponds to the difference between a trajectory setpoint, of the position setpoint type, which depends on a reference trajectory, and the actual trajectory of the vehicle, given by the measured position of the power steering, then determining, from the trajectory difference, a driver torque setpoint intended to reduce the trajectory difference.