Servomotor Control Algorithm for Steering Systems
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Classic control methods like P, PI, and PID controllers are not well-suited for the high dynamic requirements of motor vehicle steering systems, particularly due to linearity deviations and time-dependent disturbances caused by changes in vehicle dynamics, leading to instability and reduced control accuracy.
Innovation Solution
A control method that calculates the manipulated variable T1 of the servomotor using the time derivative and integral of the position deviation, incorporating terms such as proportional, integral, and differential components, along with weighting functions to improve control accuracy and reduce overshoots, ensuring robustness against internal and external disturbances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If classic control algorithms (P, PI, PID) are used, then the control system is simple to implement, but the control accuracy and stability deteriorate under high dynamic requirements and time-dependent disturbances
Solution Approach 1:
The control algorithm transitions from static P, PI, PID controllers to a dynamic model-based controller that continuously adapts to changing vehicle dynamics. The new algorithm uses time-dependent state variables and disturbance models to adjust control parameters in real-time, maintaining high accuracy under varying operating conditions while managing complexity through structured mathematical modeling.
Solution Approach 2:
The invention changes the fundamental parameters of the control approach by moving from fixed gain controllers to variable parameter controllers. The control algorithm incorporates time-varying parameters that adapt to changing system conditions, including disturbance magnitude, vehicle speed, and steering angle, thereby improving control accuracy without requiring overly complex hardware modifications.
2Device complexity
If classic control algorithms are used, then the system structure remains simple, but the system becomes unstable under linearity deviations and time-dependent disturbances
Solution Approach 1:
The invention implements enhanced feedback mechanisms that continuously monitor system state variables and disturbance parameters. The controller uses real-time feedback from position sensors, velocity measurements, and disturbance estimates to adjust control actions, ensuring stability even when system linearity deviations occur or external disturbances change over time.
Solution Approach 2:
The control algorithm performs preliminary compensation for anticipated disturbances by using a dynamic model to predict system behavior. Before disturbances significantly impact the system, the controller pre-adjusts control parameters based on predicted trends in vehicle dynamics, steering angle, and speed, thereby maintaining stability proactively rather than reactively.
3Manufacturing precision
If control algorithms are designed for high control accuracy with low overshoots, then the position control becomes robust, but the computational complexity increases
Solution Approach 1:
The control algorithm is segmented into distinct computational modules: disturbance estimation, state prediction, control parameter calculation, and output generation. Each module handles a specific aspect of the control task, allowing for optimized computation in each segment while maintaining overall high accuracy and low overshoot performance through coordinated operation of all segments.
Data Source
Figure 1~2
Figure 3
AI summary
The invention relates to a method for controlling an electric actuator, wherein a manipulated variable T1 of a servomotor is determined by a controller in order to reach a target position Xd as a target position starting from an actual position X as a state variable, and wherein a control value of the electric actuator is calculated on the basis of the manipulated variable T1, wherein the manipulated variable T1 of the servomotor is calculated by using the second time derivative of the target position d2Xd/dt2 and an achieved control change ΔΧ| Τ - ΔΧ| 0, with formula (I) and formula (II).