The research of quadruped robots is fundamentally motivated by their excellent performance in complex terrain. Maintaining the trunk moving smoothly is the basis of assuring the stable locomotion of the robot. In this paper we propose a planning and control strategy for the pacing gait of hydraulic quadruped robots based on the centroid. Initially, the kinematic model between the single leg and the robot trunk was established. The coupling of trunk motion and leg motion was elaborated on in detail. Then, the real-time attitude feedback information of the trunk was considered, the motion trajectory of the trunk centroid was planned, and the foot trajectory of the robot was carried out. Further, the joint torques were calculated that fulfillment minimization of the contact forces. The position and attitude of the robot trunk were adjusted by the presented controller. Finally, the performance of the proposed control framework was tested in simulations and on a robot platform. By comparing the attitude of the robot trunk, the experimental results show that the trunk moved smoothly with small-magnitude by the proposed controller. The stable dynamic motion of the hydraulic quadruped robot was accomplished, which verified the effectiveness and feasibility of the proposed control strategy.

Engineering drawing is an important foundational compulsory course in the field of robotics engineering major. The Outcome-based Education concept was integrated into the teaching. The problem in traditional engineering drawing course teaching was analyzed, the course content was optimized, the teaching objectives was established, the course evaluation system was constructed, and the teaching effectiveness was improved. The self-learning ability of students was improved, and the ability of students to think actively was improved. The proposed method provides certain reference suggestions for the optimization of the engineering drawing course.