Force Servoing by Flexible Manipulator Based on Resonance Ratio Control

Abstract

This paper presents a force servoing control method to suppress torsional vibration of two-mass resonant system. The resonance ratio control is one of the effective control methods of two-mass resonant system. In this method, the ratio between the resonant frequency of motor and arm is determined arbitrary according to the feedback of estimated reaction torque. The reaction torque is estimated by using position sensitive detector (PSD). Since the estimation method does not need the parameter identification, the torsion information is obtained with accuracy.To attain the affinity and adaptability to environment, motion systems should control the reaction torque from the environment. In the force servoing system, the force command is given as a disturbance of the arm portion. The arm disturbance is observed by the arm disturbance observer. The proposed force servoing system is based on both the conventional PD control and the resonance ratio control and the determination method of pole placement is discussed. The proposed force servoing system can realize both the suppression of the inner torsional reaction torque and the adaptation to unknown outer force inputs. The numerical and experimental results show viability of the proposed method. Arm Motor m J a J f K Arm Motor m J a J f K Fig. 1. Model of flexible manipulator 2 ref m J 1 J J K

Robust position control of a novel series elastic actuator via disturbance observer

“…If only two control parameters 1 K  and 2 K  are used, e.g. in [12], then the damping of the system cannot be precisely controlled; however, the vibration can be suppressed by applying extra damping which may degrade the performance.…”

Decomposed Sliding Mode Control of the Drive with Interior Permanent Magnet Synchronous Motor and Flexible Coupling

“…Hence, the electromagnetic processes control problem is reduced to a control of the electromagnetic torque. The torque reference is formed in a slow control loop of the mechanical movement, which is based on the movement equation (2). Since the value of the electromagnetic torque is defined by the DC values (as the current in the DC motor winding), the control problem for a fast internal loop is reduced to a feedback current control using the power converter.…”

“…The problem of torsional vibration elimination is prevalent not only in high-power application such as rolling-mill drives but also conveyer and cage-host drives. Today due to the progress in power electronic and microprocessor systems that allow controlling the electromagnetic torque of motor almost without any delay and expand a pass-band up to the frequencies comparable to a resonance frequencies of the controlled plant mechanical parts, the problem of torsional vibrations appears also in many medium and low-power applications such as servo-drives, throttle drives, and robot arm drives including space applications [1][2][3][4][5][6].…”

Vibration Suppression With Shaft Torque Limitation Using Explicit MPC-PI Switching Control in Elastic Drive Systems

“…Passive mode refers to the application of the notch filter [3]; Active mode can be categorized into basic PI control (two degrees of freedom PI control, RRC [4]), state feedback control based on PI, and other advanced algorithms [5].…”