Controller design and measurement for active vibration damping of skid-steer loader via displacement controlled actuators

Operators of mobile machines often suffer from unfiltered whole-body vibration that could be harmful to the health and the productivity. While researches in the industry are mainly focused on saving energy, it is actually brought to attention that energy savings and improved comfort can be realized together. A skid-steer loader that does not have a suspension can use its working hydraulic cylinders to achieve improved operator comfort and still achieve energy savings by using displacement controlled circuit. The presented work uses displacement controlled skid-steer loader to achieve active vibration damping based on skyhook damping theory. The method is simulated on three-dimensional model developed based on math and physics, and is also implemented and demonstrated on the actual prototype loader. This work also investigates on details of designing a controller for active vibration damping methods and illustrates the significance of hydraulic cylinder motion control on such active damping methods. The proposed method of active damping shows improvement in comfort rating compared not only to the base machine but also to other available damping strategies