| Cab ergonomic design is one of the important aspects in the development of large mining excavators.Good cab ergonomics is the key to successfully complete the excavation tasks and give full play to the performance of large mining excavators.Research of cab ergonomics is of great significance to improve safety,reliability and system efficiency,reduce the driver's musculoskeletal disorders,improve the level of independent design and development of large-scale mining equipment in China.This research is also important for improving the health of workers in harsh environments and creating a comfortable workspace.This study relies on the National 863 Science and Technology Fund Project(2012AA062001)and the Shanxi Provincial Coal-based Key Project(MJH2014-08).Taking the cab of large mining excavator as research object,ergonomic design method and technology were studied in depth.The main research work is as follows:(1)Based on complex relationship between human-machine-environment,a research framework system for cab ergonomic design of large mining excavators was constructed.The cab ergonomic design elements of large mining excavators were clearly defined,and the ergonomic design research tasks corresponding to each stage of development were proposed.The study provides a theoretical basis for the cab ergonomic design of large mining excavator.(2)According to driving visual field requirement of large mining excavator,a cab layout method was proposed.A model of driver's working posture was constructed,and the maximum and minimum points of excavator bucket were taken as the limit size of visual field to determine the distribution area of eye points,so the H-point layout area meeting the requirements of the field of view was obtained.This method has better adaptability and operability.Then a large mining excavator simulated operation test bed was built,and the comfort area of joystick was obtained by a layout test of joystick.The motion capture system was used to determine the operating posture comfort gradient with upper limb joint Angle as the index.The results was suitable for the prediction and analysis of excavator operation posture.(3)The man-machine interface of large mining excavator cab was studied.A three-factor mathematical model of display console layout was established with a optimal sequence as objective function.The idea of annealing was introduced into particle swarm optimization(PSO),and an improved PSO was proposed to optimize the layout of display console.Then,the man-machine interface of joystick was analyzed,and a variety of reverse design methods based on key points were proposed to obtain comfortable joystick modeling.The method is verified by specific test and analysis.The results show that the layout method of the display console and the joystick design method can meet the needs of the human-machine interface,and provide a new idea for the design of the human-machine interface of the large mining excavator.(4)Surface electromyography(s EMG)was used to measure the EMG signal of upper limbs in different operating positions,and the relationship between s EMG signal and operating posture comfort was obtained: RMS of pronator was positively correlated with comfort.A comparative experiment with or without armrest in excavator operation was designed,and the influence of armrest on muscle fatigue of upper limbs was discussed:during the long-term repeated operation,the support of armrest to upper limb can make operation easier and effectively reduce fatigue.Among them,armrest had the largest effect on deltoid muscle,followed by ulnar wrist extensor and radial flexor tendon,and had less effect on biceps and pronator.(5)Taking the cab of actual large mining excavator as an example,based on JACK,the cab ergonomics was analyzed,the main problems were put forward,and the optimization design was carried out. |
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