Research On Human Body Turning-over Mechanics For Nursing Robot

In recent years,the care of patients who have lost their ability to take care of themselves has brought a heavy burden on families and society.Nursing machines can meet the function of turning-over,and can relieve the pressure that nurses work for the patients and the labor intensity of nursing.Ensuring the safety of the patient is the first thing to complete the turning-over movements for nursing machines.Human-like turning-over activity can do it well.In this paper,Human-like turning-over activity is used to simulate the joint torque and muscle force of the human model.At the same time,the corresponding theoretical calculation process is analyzed.We do a lot in terms of torque analysis.After referring to the various postures,we determined the postures are direct turning-over,unilateral lower limb lift turning-over,unilateral upper and lower limb lift turning-over,and standard-like turning-over.And then,we find the perferable postures for the disabled patients.According to the physiological characteristics of the human body,the rigid ball-and-stick model of the patients' turning-over movement is established.We do the simulation to obtain the simulated joint torque and find the dangerous joints.According to the Newton-Euler method,the theoretical calculation of the joint torque of the human body is carried out,and the theoretical calculation of the joint torque is obtained.Comparing the theoretical value with the simulation value,the conclusion that the change trend is basically the same,which shows the rationality of the theoretical calculation.The theoretical calculation based on the Newton-Euler method can provide the turning-over movements of the nursing machines in terms of joint torque.It also can provide the data reference for muscle force calculation.We also do a lot in the analysis of muscle force.Firstly,according to the joint torque,we calculate the muscle forces based on the minimum optimization of the square of the muscle force.And then,we carry out the inverse dynamics simulation of the turning-over movement of the human skeleton-muscle model,and find out the dangerous muscles simulated in the turning movements to obtain the muscle forces of the dangerous muscles.Comparing the theoretical value with the simulation value,the conclusion that the change trend is basically the same,which shows the rationality of the theoretical calculation.Next,we compare the muscle activity of dangerous muscles with their muscle forces.According to the consistent trend,it is concluded that there is a positive correlation between the two parts.It is believed that muscle strength can provide a reference for muscle injury.Muscle force calculation based on the minimum optimization of the square of the muscle force can provide theoretical support for the turning-over movements of nursing machines in terms of muscle force.Finally,we do the experimental verification based on EMG signal.The turning-over activity is carried out and we get the EMG signal.The EMG signal is integrated to obtain the curve of EMG integral of turning-over movement.We make the curve of EMG integral together with the theoretically calculated muscle force to compare their trends.the consistency of the trends is obtained,which proves the correctness of the theoretical calculation and simulation analysis of muscle strength.