Actuator Control Method Using Feedback Time Optimal Switching

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Solution Overview

Problem

Conventional actuator control methods, such as PID control, face instability and overshoot due to load fluctuations, and time optimal control lacks feedback elements, making it difficult to accurately stop a controlled object at a target position in the shortest time.

Innovation Solution

The actuator control method employs 'feedback time optimal control' by calculating and updating switching times for maximum acceleration and deceleration outputs, incorporating feedback to stabilize control and reduce residual energy, and uses energy comparisons to switch between driving and braking, allowing for stable control even with changing external forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PID control is used to ensure stability, then control stability is improved, but control speed decreases and overshoot occurs due to load fluctuation

Engineering Contradiction:
Improvecontrol stabilityVSAvoidcontrol speed
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The patent applies feedback by continuously monitoring the controlled object's state and adjusting the control output accordingly. The feedback mechanism compares the actual state with the target state and modifies the control signal to minimize the difference, enabling the system to adapt to load fluctuations and achieve both stability and speed.

Inventive Principle:
Principle #23Feedback

2Speed

If time optimal control is used to stop the controlled object in the shortest time, then control speed is improved, but accuracy decreases because there is no feedback element

Engineering Contradiction:
Improvecontrol speedVSAvoidpositioning accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent incorporates feedback elements into the time optimal control framework. By continuously measuring the controlled object's position and velocity and comparing them with the optimal trajectory, the system can correct deviations caused by disturbances or model inaccuracies, thereby achieving both fast response and high positioning accuracy.

Inventive Principle:
Principle #23Feedback

3Reliability

If sliding mode control is used to eliminate the influence of load fluctuation, then control stability is improved, but control complexity increases and oscillation occurs if the control period is lengthened

Engineering Contradiction:
Improvecontrol stabilityVSAvoidcontrol complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs parameter changes by dynamically adjusting control parameters based on the system's current state and operating conditions. This allows the controller to maintain stability across varying load conditions without requiring complex switching logic, thereby reducing control complexity while eliminating the influence of load fluctuations.

Inventive Principle:
Principle #35Parameter changes

4Speed

If control gains are increased to increase control speed in PID control, then control speed is improved, but control becomes unstable and may diverge

Engineering Contradiction:
Improvecontrol speedVSAvoidcontrol stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies dynamics by making the control gains variable rather than fixed. The control parameters are dynamically adjusted based on the system's real-time state, allowing the controller to achieve high response speed when needed while maintaining stability during transient conditions or when mechanical damping is reduced.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2752718B1Actuator control method and actuator control device
Publication Date: 2017.10.04 ISUZU MOTORS LTD
  • EP2752718B1 patent drawingFigure 1
  • EP2752718B1 patent drawingFigure 2
  • EP2752718B1 patent drawingFigure 3

AI summary

By an actuator control method and an actuator control device that perform "energy evaluation control" that compares kinetic energy of a controlled object and work that can be done by braking and switches driving to braking at a point of time at which the kinetic energy of the controlled object and the work that can be done by braking become equal, and also repeatedly makes a comparison between the kinetic energy of the controlled object and the work that can be done by braking at each preset time, as a new control method that replaces PID control in mechanics for effectively utilizing vehicle energy to improve vehicle fuel consumption and control methods thereof, a control result is obtained by a simpler method.