Torque modeling and control algorithm of a permanent magnetic spherical motor

Author(s):  
Zhe Qian ◽  
Qunjing Wang ◽  
Lufeng Ju ◽  
Anbang Wang ◽  
Jun Liu
1996 ◽  
Vol 118 (1) ◽  
pp. 29-40 ◽  
Author(s):  
Kok-Meng Lee ◽  
Ronald B. Roth ◽  
Zhi Zhou

Examination of existing joint designs for robot wrist applications has indicated that a spherical wrist motor offers a major performance advantage in trajectory planning and control as compared to the popular three-consecutive-rotational joint wrist. The tradeoff, however, is the complexity of the dynamic modeling and control. This paper presents the dynamic modeling and the control strategy of a three degree-of-freedom (DOF) variable-reluctance (VR) spherical motor which presents some attractive possibilities by combining pitch, roll, and yaw motion in a single joint. The spherical motor dynamics consist of the rotor dynamics and a torque model. The torque model is described as a function of coil excitations and a permeance model in terms of the relative position between the rotor and the stator. Both the forward dynamics which determine the rotor motion as a result of activating the electromagnetic coils and the inverse model which determines the coil excitations required to generate the desired torque are derived in this paper. The solution to the forward dynamics of the spherical motor is unique, but the inverse model has many solutions and therefore an optimization is desired. Experimental results verifying the dynamic model are presented. The control of a VR spherical motor consists of two parts; namely, the control of the rotor dynamics with the actuating torque as system input, and the determination of the optimal electrical inputs for a specified actuating torque. The simulation results and implementation issues in determining the optimal control input vectors are addressed. It is expected that the resulting analysis will serve as a basis for dynamic modeling, motion control development, and design optimization of the VR spherical motor.


2018 ◽  
Vol 27 (03n04) ◽  
pp. 1840014
Author(s):  
Kiarash Ahi

This paper presents a novel control algorithm for a modular high-frequency converter. This control algorithm is designed to achieve an effective frequency higher than the switching frequency on the passive elements. As a result, the ripple on the output is suppressed, and smaller capacitors can be used. In this work, the modular high-frequency converter is modeled by equivalent boost converters. Based on the equivalent models a control algorithm is developed. The accuracy of the algorithm has been verified by simulation results using PLECS in the MATLAB/Simulink environment.


2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
S. Sadr ◽  
S. Ali A. Moosavian ◽  
P. Zarafshan

Nowadays, aerial robots or Unmanned Aerial Vehicles (UAV) have many applications in civilian and military fields. For example, of these applications is aerial monitoring, picking loads and moving them by different grippers. In this research, a quadrotor with a cable-suspended load with eight degrees of freedom is considered. The purpose is to control the position and attitude of the quadrotor on a desired trajectory in order to move the considered load with constant length of cable. So, the purpose of this research is proposing and designing an antiswing control algorithm for the suspended load. To this end, control and stabilization of the quadrotor are necessary for designing the antiswing controller. Furthermore, this paper is divided into two parts. In the first part, dynamics model is developed using Newton-Euler formulation, and obtained equations are verified in comparison with Lagrange approach. Consequently, a nonlinear control strategy based on dynamic model is used in order to control the position and attitude of the quadrotor. The performance of this proposed controller is evaluated by nonlinear simulations and, finally, the results demonstrate the effectiveness of the control strategy for the quadrotor with suspended load in various maneuvers.


2011 ◽  
Vol 383-390 ◽  
pp. 760-763
Author(s):  
Hong Jun Wang ◽  
De Xiong Li ◽  
Hui Juan Qi ◽  
Li Na Liu

e furnace of steel plant is a complex controlled object and it has the properties of nonlinear, Time-varying and delay. Its modeling and control are very difficult. The temperature control of the furnace mainly depends on the control of gas flow. Therefore, the study of a reasonable gas flow control program is the key to increase the level of heating control. In this paper, an improved fuzzy PID control algorithm is proposed, in which, PID control algorithm and fuzzy control algorithm are integrated together, and its characteristics are improved according to feature of furnace. This made the algorithm to have good adaptability and Interference capability. The simulation results show that the improved control algorithm is better than traditional algorithm in overcoming the non-liner, delay of the object and the performance is excellent.


2011 ◽  
Vol 35 (4) ◽  
pp. 543-557 ◽  
Author(s):  
Mohammad A. Khosravi ◽  
Hamid D. Taghirad

In this paper modeling and control of cable driven redundant parallel manipulators with flexible cables, are studied in detail. Based on new results, in fully constrained cable robots, cables can be modeled as axial linear springs. Considering this assumption the system dynamics formulation is developed using Lagrange approach. Since in this class of robots, all the cables should remain in tension for the whole workspace, the notion of internal forces are introduced and incorporated in the proposed control algorithm. The control algorithm is developed in cable coordinates in which the internal forces play an important role. Finally, asymptotic stability of the closed loop system is analyzed through Lyapunov theorem, and the performance of the proposed algorithm is studied by simulations.


Drones ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 92
Author(s):  
José Antonio Bautista-Medina ◽  
Rogelio Lozano ◽  
Antonio Osorio-Cordero

This paper proposes a simple flying rotor prototype composed of two small airplanes attached to each other with a rigid rod so that they can rotate around themselves. The prototype is intended to perform hover flights with more autonomy than existing classic helicopters or quad-rotors. Given that the two airplanes can fly apart from each other, the induced flow which normally appears in rotorcrafts will be significantly reduced. The issue that is addressed in the paper is how this flying rotor prototype can be modeled and controlled. A model of the prototype is obtained by computing the kinetic and potential energies and applying the Euler Lagrange equations. Furthermore, in order to simplify the equations, it has been considered that the yaw angular displacement evolves much faster than the other variables. Furthermore a study is presented to virtually create a swashplate which is a central mechanism in helicopters. Such virtual swashplate is created by introducing a sinusoidal control on the airplanes’ elevators. The torque amplitude will be proportional to the sinusoidal amplitude and the direction will be determined by the phase of the sinusoidal. A simple nonlinear control algorithm is proposed and its performance is tested in numerical simulations.


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