Steering Servoassistance Compensation for Transmission Error
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing steering systems in road vehicles suffer from transmission errors due to non-straight transmission lines, leading to variations in steering effort and reduced driving sensitivity, which are difficult to mitigate without imposing geometrical constraints that increase design and assembly complexity and cost.
Innovation Solution
A method and unit that utilize a servomechanism with an electrical actuator and electronic control unit to apply a variable servoassistance force, adjusting the force needed to turn the steering wheel based on real-time detection of the steering wheel's angular position and torque, thereby compensating for transmission errors without strict mechanical constraints.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a non-straight transmission line is used to connect the steering wheel and steering box, then the design and assembly flexibility is improved, but transmission error increases leading to reduced driving sensitivity
Solution Approach 1:
The system measures the actual transmission error through sensors detecting the steering wheel angular position and torque, then feeds this information back to the control unit which calculates compensatory servoassistance forces. This closed-loop feedback mechanism allows the system to adapt to the non-straight transmission line configuration while maintaining accurate steering control.
Solution Approach 2:
The control unit dynamically adjusts the servoassistance force parameters based on the measured transmission error characteristics. By changing the magnitude and direction of the compensatory force as a function of steering angle and torque, the system optimizes steering accuracy despite the fixed geometric constraints of the non-straight transmission line.
2Manufacturing precision
If geometrical constraints are imposed on the transmission line setup to reduce transmission error, then driving sensitivity is improved, but design and assembly complexity increases
Solution Approach 1:
The patent replaces the need for precise mechanical alignment with an electromechanical compensation system. Instead of constraining the transmission line geometry to minimize error, the system uses an electrical actuator and control unit to generate compensatory forces, substituting mechanical precision requirements with electronic control.
Solution Approach 2:
The servomechanism acts as an intermediary between the driver's steering input and the steering box. It introduces a compensatory force that mediates the transmission error, allowing the transmission line to maintain its flexible non-straight configuration while still achieving accurate steering control.
3Manufacturing precision
If a servomechanism with electrical actuator is added to compensate for transmission error, then transmission accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The servomechanism is integrated into the existing steering system architecture, serving multiple functions: it provides power assistance during normal operation and simultaneously compensates for transmission errors. This multi-functionality reduces the need for separate compensation mechanisms, thereby limiting the increase in overall system complexity.
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 approach allows for reduced transmission errors, improving driving sensitivity and perception by compensating for mechanical transmission errors through a servoassistance force, thus optimizing steering without increasing design complexity or cost.
Implementation Method 1
an electrical actuator (16) adapted to apply a variable servoassistance force
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method and unit (18) to control a steering system (4) for a road vehicle (1), which steering system (4) adjusts the steering angle of the front wheels (2) of the road vehicle (1) by means of a steering wheel (6); in a preliminary design and optimization step, an actual transmission error (εTREAL) is determined, caused by the mechanical structure of a transmission device (7) of the steering wheel which mechanically connects a steering wheel (6) to a steering rod (5) mechanically connected to the hubs of the front wheels (2); the current angular position of the steering wheel (6) is measured; and the intensity of the servoassistance force applied by a servomechanism (15) to the steering rod (5) is changed as a function of the current angular position of the steering wheel (6) and as a function of the actual transmission error (εTREAL).