Optimal Control of Semi-Active Suspension for Agricultural Tractors Using Linear Quadratic Gaussian Control.

Area of Science:

• Agricultural Engineering
• Control Systems Engineering
• Mechanical Engineering

Background:

• Tractor ride vibrations negatively impact operator comfort and productivity.
• Existing suspension systems may not adequately address dynamic vibration challenges.
• Hydro-pneumatic systems offer potential for advanced suspension control.

Purpose of the Study:

• To design and validate a semi-active suspension system for tractors.
• To minimize ride vibration using a hydro-pneumatic mechanism and a control algorithm.
• To improve tractor cabin comfort and operational efficiency.

Main Methods:

• Developed a semi-active suspension utilizing a hydro-pneumatic mechanism.
• Designed a linear-quadratic-Gaussian (LQG) optimal control algorithm for suspension control.
• Modeled the tractor using actual parameters and employed a Kalman-filter-based state observer for state estimation.
• Validated the state observer's accuracy for vertical velocity (83%) and acceleration (79%).

Main Results:

• The LQG controller significantly reduced tractor cabin vertical acceleration.
• Peak vertical acceleration decreased by up to 48.97%.
• Root-mean-square vertical acceleration decreased by up to 47.06% compared to a rubber mount system.

Conclusions:

• The designed semi-active suspension effectively minimizes ride vibrations in tractors.
• The LQG control algorithm and Kalman filter provide accurate state estimation and control.
• This technology offers a pathway to reduced system costs and improved agricultural machinery design.