High-Performance Control of Dual-Inertia Servo-Drive Systems Using Low-Cost Integrated SAW Torque Transducers

Abstract

Abstract-This paper provides a systematic comparative study of compensation schemes for the coordinated motion control of two-inertia mechanical systems. Specifically, classical proportional-integral (PI), proportional-integral-derivative (PID), and resonance ratio control (RRC) are considered, with an enhanced structure based on RRC, termed RRC+, being proposed. Motor-side and load-side dynamics for each control structure are identified, with the "integral of time multiplied by absolute error" performance index being employed as a benchmark metric. PID and RRC control schemes are shown to be identical from a closed-loop perspective, albeit employing different feedback sensing mechanisms. A qualitative study of the practical effects of employing each methodology shows that RRC-type structures provide preferred solutions if low-cost high-performance torque transducers can be employed, for instance, those based on surface acoustic wave technologies. Moreover, the extra degree of freedom afforded by both PID and RRC, as compared with the basic PI, is shown to be sufficient to simultaneously induce optimal closed-loop performance and independent selection of virtual inertia ratio. Furthermore, the proposed RRC+ scheme is subsequently shown to additionally facilitate independent assignment of closed-loop bandwidth. Summary attributes of the investigation are validated by both simulation studies and by realization of the methodologies for control of a custom-designed two-inertia system. Index Terms-Acceleration control, motion control, resonance, surface acoustic wave (SAW) devices, torque control, velocity control, vibration control.Motor electromagnetic torque (N · m).Load-side torque (N · m). t md Torsional shaft torque (N · m). ω n Mechanical resonant frequency (rad/s).

Observer-Based Tuning of Two-Inertia Servo-Drive Systems With Integrated SAW Torque Transducers

“…In such cases, the servodrive system can be modeled using a two-inertia approximation [1]- [14], [16], [18], [19]. Fig.…”

“…The motor angular velocity is denoted ω m , and the load velocity is denoted ω d . Since damping losses are usually considered to be relatively low, they are neglected without significantly affecting the accuracy of the forgoing analysis [1]- [14], [16], [18], [19]. Fig.…”

“…By augmenting the basic controller with the feedback of additional state variables, enhanced disturbance rejection performance can be achieved [1]- [12], [18], [19]. The general structure of such an extended controller is shown in Fig.…”

“…Furthermore, K s and K d represent the transfer feedback gains associated with shaft torque and the estimated motor acceleration feedback (from second derivative of angular position), respectively. For example, setting K pd , K dd , and K d to zero provides a PI controller with shaft torque feedback, referred to as RRC [1]. Alternatively, setting K pd , K dd , and K s to zero provides a classical PID control scheme [18] (i.e., employed when shaft torque feedback is not available).…”

Controller Design for Three-Mass Resonant System Based on Polynomial Method

“…This simplified approach has been used in different industrial applications [6][7][8]. Vibration suppression and high speed response control in motion control system is an important problem in industry applications [9][10][11]. Control problems of a multi-mass system is especially difficult when not all system variables are measurable, which happens very often in industrial applications [12,13].…”