A review of heavy-duty legged robots

Heavy-duty legged robots have been regarded as one of the important developments in the field of legged robots because of their high payload-total mass ratio, terrain adaptability, and multitasking. The problems associated with the development and use of heavy-duty legged robots have motivated researchers to conduct many important studies, covering topics related to the mechanical structure, force distribution, control strategy, energy efficiency, etc. Overall, heavy-duty legged robots have three main characteristics: greater body masses, larger body sizes, and higher payload-total mass ratios. Thus, various heavy-duty legged robots and their performances are reviewed here. This review presents the current developments with regard to heavy-duty legged robots. Also, the main characteristics of high-performance heavy-duty legged robots are determined and conclusions are drawn. Furthermore, the current research of key techniques of heavy-duty legged robots, including the mechanical structure, force distribution, control method, and power source, is described. To assess the transportation capacity of heavy-duty legged robots, performance evaluation parameters are proposed. Finally, problems that need further research are addressed.