Life care for disabled or semi-disabled elderly has become an increasingly common problem in society. In this paper, a novel wheelchair-stretcher assistive robot, which can meet the physiological needs of patients, is investigated and designed. The following tasks are conducted: (1) the mecanum wheel is adopted as the executive device of the walking mechanism, and its kinematics is analyzed in detail. (2) A five-link mechanism with single degree of freedom is proposed to realize the folding motion of the robot. Through the minimum conclusive area method, the optimal sizes of the armrests link and the side link are 507.9, and 332.5 mm, respectively. Based on the force analysis of the linkage mechanism, six torsion springs and RV (rotate vector) reduction motor are used as the driving device, which reduces the driving torque of the motor. (3) Based on the STM32 (STMicroelectronics 32-bits Microcontroller) chip, and combined with the theoretical analysis, the mechanical structure and the control system of the whole prototype are designed, and the feasibility of each module is verified by experimental research. The results confirm that the proposed robot has good performance, and that the control algorithm for the walking mechanism and the lifting mechanism are suitable.

Person transfer is a major problem for nursing in home and clinical, and this problem is becoming more prominent with the development of aging society and the change of population structure. In this article, a novel person transfer assist system named E-Pat (Easy-Patient Transfer), which can meet the transfer needs of the patient between beds, has been designed and analyzed. The importance and originality of this study are that it explores a theoretical design method for device to enhance patient comfortably when transferred, and put it into practice. The main tasks completed in this article include: (1) a prototype of the device is designed based on the principle of relative static contact point theory. In addition, the corresponding relationship between the human body pressure and the insertion angle is proposed, which provides a theoretical basis for the optimization of the mechanism; (2) based on STM32 (STMicroelectronics 32-bits Microcontroller) chip, the hardware circuit part of the device is designed. According to the transfer environment requirements of the device, the synchronization control algorithm of the device is designed and the experiment is carried out; (3) the performance evaluation of the device is carried out by means of Analytic Hierarchy Process (AHP), through the research of a group of 30 volunteers, the performance of the system has been evaluated accurately, which provides a reference for the industrialization of the prototype. The whole research of this article proves that this kind of person transfer assist system has good performance, it can also reduce the burden of caregivers.

It is desired to require a walking robot for the elderly and the disabled to have large capacity, high stiffness, stability, etc. However, the existing walking robots cannot achieve these requirements because of the weight-payload ratio and simple function. Therefore, Improvement of enhancing capacity and functions of the walking robot is an important research issue. According to walking requirements and combining modularization and reconfigurable ideas, a quadruped/biped reconfigurable walking robot with parallel leg mechanism is proposed. The proposed robot can be used for both a biped and a quadruped walking robot. The kinematics and performance analysis of a 3-UPU parallel mechanism which is the basic leg mechanism of a quadruped walking robot are conducted and the structural parameters are optimized. The results show that performance of the walking robot is optimal when the circumradius R, r of the upper and lower platform of leg mechanism are 161.7 mm, 57.7 mm, respectively. Based on the optimal results, the kinematics and dynamics of the quadruped walking robot in the static walking mode are derived with the application of parallel mechanism and influence coefficient theory, and the optimal coordination distribution of the dynamic load for the quadruped walking robot with over-determinate inputs is analyzed, which solves dynamic load coupling caused by the branches’ constraint of the robot in the walk process. Besides laying a theoretical foundation for development of the prototype, the kinematics and dynamics studies on the quadruped walking robot also boost the theoretical research of the quadruped walking and the practical applications of parallel mechanism.

This article adopts a 2-UPS+UP (U, P, and S are universal joint, the prismatic joint, and sphere joint, respectively) parallel mechanism as the leg mechanism of the quadruped walking robot based on the bionic concept and the motion capacity of the leg mechanism. The article investigates the kinematics (including the leg mechanism and the whole mechanism), gait planning, control, and experiment in detail. The following tasks are conducted: (1) designing the whole mechanism and developing the kinematics equations for both the leg mechanism and the whole mechanism; (2) planning the trotting gait and designing the foot trajectory based on the robot characteristics and conducting the kinematics analysis; (3) building the control system of the robot using self-developed controllers and drivers and studying the compound position control strategy; and (4) conducting the experiments for validating the controller, the compound position control strategy, the trotting pace, carrying capacity, and human-carrying walking. The results confirm that the proposed human-carrying walking robot has good performance and it is also verified that the controller and the compound position control strategy are suitable.

Patient transfer has always been a difficult problem in the hospital. For medical staff, there are problems including high risk of infection, heavy physical labor and low efficiency of transfer; for patients, there are problems including poor comfort and secondary injury. In this paper, a novel bilateral patient transfer robot is investigated and designed. The following tasks are conducted: (1) Based on the process of patient transfer, a transfer model, which consists of two degrees of freedom, is proposed, and the working principle of bilateral patient transfer robot is obtained and analyzed in detail. (2) Force analysis of the patient transfer robot is conducted. The corresponding relationship between the patient comfort and the insertion angle is proposed, and the optimal sizes of mechanical structure are obtained. (3) Based on the theoretical analysis, the mechanical structure and the control system of the robot are designed, and the prototype is manufactured. (4) Experimental research is conducted. The results show that the prototype can complete the required motion performance with a carrying capacity up to 150 kg and patient comfort is excellent. The results of this paper prove that this kind of patient transfer robot has good performance, it can also reduce the burden on medical staff.