Cunjin Ai

The rationality of gait analysis directly affects the dynamics of human lower limbs in the sagittal plane, and recent studies on gait stage redivision lack the stage when both feet are not in complete contact with the ground. This paper proposes a novel variable pivot gait, which includes the stage when the heel of one foot and the toe of the other are in contact with the ground and a dynamics correction method based on this gait. First, the relative motion data between the foot and the ground are measured by motion capture experiments, and then a variable pivot gait is proposed in terms of the pivot transformation between the foot and the ground. Second, the dynamics modeling is conducted based on the principle of mechanisms of human lower limbs in each stage of the variable pivot gait. Third, a dynamics correction method is proposed to correct the foot dynamics when the foot is not in complete contact with the ground. The experiment and simulation show that the variable pivot gait is consistent with the actual motion of the foot relative to the ground. The effectiveness of the dynamics correction method is proved by comparing dynamics results (hip, knee, and ankle moments) with previous studies. The variable pivot gait and the dynamics correction method can be applied to the human lower limbs and lower-limb robots, providing a new avenue.

In this paper, the “EX1016 - low air pressure” alarm that occurs in the VDF-850 vertical machining center (FANUC-0i-Mate-MD system) produced by Dalian Dalian Machine Tool Factory causes the machine to fail to start the cycle as an example, and describes the generation of air pressure. Low working principle, troubleshooting method, modification of PMC ladder diagram, etc., and timely troubleshooting, to ensure normal teaching and production.

This paper takes the failure of the spindle command speed and the actual output speed mismatch caused by the CK6136 horizontal CNC lathe (FANUC-0i-TD system) produced by Dalian Dalian Machine Tool Plant as an example. The hardware connection and spindle override of the analog spindle control circuit are described. PMC program design, spindle parameter setting, inverter parameter setting and theoretical calculation of main parameters, etc., and successfully debugged on the CNC lathe in the laboratory.