High-Speed,High-Power Motor Design for a Four-Legged Robot Actuator Optimized using the Weighted Sum and Response Surface Methods

In this paper,a design is presented for a high-speed,high-power motor for a four-legged robot actuator that was optimized using the weighted sum method(WSM)based on the Taguchi method,and the response surface method(RSM).First,output torque,torque constant,torque ripple,and efficiency were selected as objective functions for the optimized design.The sampling method was implemented to use a mixed orthogonal array and the single response characteristics of each objective function were compared using the Taguchi method.Moreover,to consider the multi-response characteristic of the objective functions,WSM was applied.Second,the 2D finite element analysis result of the RSM was compared with that using the WSM.Finally,an experiment was carried out on the manufactured motor and the optimized model is presented here.

Development of agricultural bionic four-legged robot:Effect of head movement adjustment on the stability of goats

The four-legged bionic robot for agriculture has been one of the hotspots in the field of robotics.The farmland environment is complex,and the balance requirement of quadruped bionic robot is higher.However,head adjustment is a key factor affecting the balance of quadruped animals.Based on this,this study takes the four-legged animal goat as an example to investigate the effect of goat head movement adjustment on the balance of goat.In this study,the head and neck of goats were simplified to a two-link model.The kinematics model was established by D-H method.MATLAB software was used to solve it.Origin software was used to draw the movement track of the center of mass of the head.The center of mass movement of the head is a quarter ellipse.Then,the goat walking experiments were carried out on the different slopes(0°,5°,10°,15°,20°,25°,30°,35°and 40°).MATLAB software was used to fit the movement data of goat head.The movement of the center of mass of the goat's head corresponds to Fourier 6.The result is:the determination coefficient is 0.8629,and the mean variance is 0.019.When the slope gradient gradually increases,the volatility gradually increases and is cyclical.The results of this study verify the rationality of the four-legged bionic mechanism under various parameters and reveal the mechanism of goat walking with an appendage at the head.

The Control Technology Research of the Z-source Three-phase Four-bridge Arm Inverter

Z-source inverter can boost the voltage of the DC-side, allow the two switches of the same bridge arm conducting at the same time and it has some other advantages. The zero-sequence current flows through the fourth leg of the three-phase four-leg inverter so the three-phase four-leg inverter can work with unbalanced load. This paper presents a Z-source three-phase four-leg inverter which combines a Z-source network with three-phase four-leg inverter. The circuit uses simple SPWM modulation technique and the fourth bridge arm uses fully compensated control method. The inverter can maintain a symmetrical output voltage when the proposed scheme under the unbalanced load.

A Novel Boost Four-Leg Converter for Electric Vehicle Applications

Integrating the electric vehicle into grid or microgrid has been receiving more and more attention in recent years.Typically,the electric vehicle(EV)chargers with their power batteries have been developed for vehicle-to-home(V2H)applications,acting as a backup generation to supply emergency power directly to a home.Traditional EV chargers in V2H applications mainly consist of DC/DC and DC/AC stages,which complicate the control algorithm and result in low conversion efficiency.In order to solve this problem,a novel EV charger is proposed for V2H applications.It can boost the battery voltage and output AC voltage with only one-stage power conversion.Also,the DC,1-phase and 3-phase loads can be fed with the proposed single-stage EV charger.The system control strategy is also provided to deal with versatile load variations.Finally,the performance evaluation results verify the effectiveness of the proposed solution.