A Haptically Enhanced Operational Concept for a Hydraulic Excavator

In mobile hydraulic machines, like excavators, backhoe loaders, wheel loaders, and forklift trucks, haptic human-machine interfaces are not in use. Today, the machines are operated with mechanical-hydraulic joysticks. Each joystick axis controls a single hydraulic actuator. This leads to not very easy to use operational concepts. Since electrohydraulic systems with electronic joysticks are available for serial applications, alternative operational concepts become feasible. A known alternative is to control the machine using an operating device whose segments resemble the manipulator geometry, as shown in Fig. 1 (Uchino et al., 1977). This operational concept is often called coordinated control. Typically, a master-slave system is employed where the operating device (master) outputs the reference position to the position control loop of the machine (slave). This concept promises an intuitive operation of the machine.