Design of Load and Bale Density Monitoring and Control System for a Wheeled Self-Propelled Square Baler

Abstract

HIGHLIGHTSA load and bale density monitoring and control system for a wheeled self-propelled square baler is proposed.A hydraulic circuit and weighing device are designed, and a bale density control model is established on this basis.The relationships among the main parameters affecting the operation of the control system are determined.The control system improved the automation and reliability of the square baler machine as a low-cost solution.Abstract. This study investigated baler load monitoring and automatic adjustment of bale density. A load monitoring and bale density adjustment system was developed for a wheeled self-propelled square baler. To realize the proposed system, a hydraulic circuit and a weighing device were designed, a bale density control program was developed, and a bale density control model was established. Bench tests were performed to obtain the relationships among the feed quantity of the baler, the load of the hydraulic cylinder on the compression chamber sidewall, the bale density, the piston’s compression force, the bale weight, and the degree of bale compression. The relationships among the operating parameters provided basic data for baler load monitoring and intelligent control of bale density. Field tests showed that when the bale density threshold was set at 5 kg m-3 and the allowable deviation was 2 kg m-3, the coarse adjustment time was less than 5 s, and the adjustment deviation of the bale density was within 5% as a whole, while most of the deviations were within 3%. The results demonstrate that the proposed control system can realize automatic adjustment of bale density according to user requirements within the allowable range. In addition, the proposed system can ensure stable operation and provide a reference for optimization and intelligent control of balers. Keywords: Bale density, Feeding load, Monitoring and control system, Square baler.