Design of a haptic controller for excavators

[摘要] The input orientation of the excavators in use today usually comprisestwo joysticks that control the actuator links individually. In order to performan excavation task, several different combinations of joystick inputsare required, placing high psychomotor demands on the operator.In training an operator this creates a steep learning curve, with a lengthytraining time and a reasonable amount of experience being required toperform an excavation task skilfully. In this master's thesis a haptic1 devicewas developed, resolving input ergonomics and creating a singleinput device capable of providing feedback to the operator. The designand construction of the haptic device, with the related control scheme, ispresented and discussed. The control scheme combines position and ratecontrol, and relates all the actuator joint positions to a single end-effectorpoint. The control and ergonomic aspects of the haptic device were testedand compared to the traditional two joystick control setup by means ofthe implementation of a virtual excavator simulator. The simulation wasdeveloped in MATLAB, and virtual excavator displayed in an openGLwindow. The objective of this study was to evaluate the human factorsrelated to the input orientation. Ten inexperienced test subjects were recruitedto perform four sets of tests, where each test required a differentlevel of operator skill. The results indicated that, on average, the test subjectshad an increased level of performance after training on the hapticdevice. These results strongly support the hypothesis that haptic controlsimplifies the operational tasks required for operating an excavator.1The word haptic means of, or relating to, the sense of touch, or tactile

[发布机构] Stellenbosch University