Observer-based tuning of two-inertia servo-drive systems with integrated SAW torque transducers

This paper proposes controller design and tuning methodologies that facilitate the rejection of periodic load-side disturbances applied to a torsional mechanical system while simultaneously compensating for the observer’s inherent phase delay. This facilitates the use of lower-bandwidth practically realizable disturbance observers. The merits of implementing full- and reduced-order observers are investigated, with the latter being implemented with a new low-cost servo-machine-integrated highband width torque-sensing device based on surface acoustic wave (SAW) technology. Specifically, the authors’ previous work based on proportional–integral–derivative (PID) and resonance ratio control (RRC) controllers (IEEE Trans. Ind. Electron., vol. 53, no. 4, pp. 1226–1237, Aug. 2006) is augmented with observer disturbance feedback. It is shown that higher-bandwidth disturbance observers are required to maximize disturbance attenuation over the low-frequency band (as well as the desired rejection frequency), thereby attenuating a wide range of possible frequencies. In such cases, therefore, it is shown that the RRC controller is the preferred solution since it can employ significantly higher observer bandwidth, when compared to PID counterparts, by virtue of reduced noise sensitivity. Furthermore, it is demonstrated that the prototype servo-machine-integrated 20-N · mSAWtorque transducer is not unduly affected by machine-generated electromagnetic noise and exhibits similar dynamic behavior as a conventional instrument inline torque transducer

Improved performance of motor-drive systems by SAW shaft torque feedback

The paper describes the application of a non-contact, high bandwidth, low cost, SAW-based torque measuring system for improving the dynamic performance of industrial process motor-drive systems. Background to the SAW technology and its motor integration is discussed and a resonance ratio control (RRC) technique for the coordinated motion control of multi-inertia mechanical systems, based on the measurement of shaft torque via a SAW-based torque sensor is proposed. Furthermore, a new controller structure, RRC plus disturbance feedback is proposed, which enables the controller to be designed to independently satisfy tracking and regulation performance. A tuning method for the RRC structure is given based on the ITAE index, normalized as a function of the mechanical parameters enabling a direct performance comparison between a basic proportional and integral (PI) controller. The use of a reduced-order state observer is presented to provide a dynamic estimate of the load-side disturbance torque for a multi-inertia mechanical system, with an appraisal of the composite closed-loop dynamics. The control structures are experimentally validated and demonstrate significant improvement in dynamic tracking performance, whilst additionally rejecting periodic load side disturbances, a feature previously unrealisable except by other, high-gain control schemes that impose small stability margins

Automatic controls and regulators: A compilation

Devices, methods, and techniques for control and regulation of the mechanical/physical functions involved in implementing the space program are discussed. Section one deals with automatic controls considered to be, essentially, start-stop operations or those holding the activity in a desired constraint. Devices that may be used to regulate activities within desired ranges or subject them to predetermined changes are dealt with in section two

Design and Implementation of No Load, Constant and Variable Load for DC Servo Motor

Simulations were conducted to improve and design an appropriate control system and obtain a model with the required development to suit the operation of the engine with constant and variable loads, which are the proposed working conditions that are suitable for many applications. The current simulation aims to build and design a model for an electric motor (DC Servo motor) and a model for a conventional controller (PID). The proposed model addresses the cases of fixed and variable loads in terms of using the controller that improves the performance of the motor’s work for different conditions. Three cases were developed to conduct the proposed tests, which included the case of no-load, fixed and variable load. Tests were conducted. Without the console and for the purpose of comparison and observation of improvement, the test was conducted with the addition of the console. The results showed system performance may improve depending on usage using traditional control systems. Performance measurement criteria are adopted for the purpose of comparison and observation of performance improvement. The criteria that are adopted are rise time and stability (steady state) in addition to the ratio of the rate of under and over-shoot. Where it can be deduced from this the possibility of using different control systems, including traditional ones, to improve performance, and they include controlling the speed of the motors, as well as controlling the effort, and the consequent effects on the subject of the study, as it deals with transient cases and changing operating conditions with more than acceptable efficiency and relatively high quality. There are four state simulation include, 1st at no load without controller: rise time equal  309.886ms , overshoot equal  44.203% and undershoot equal 9.597%.2nd  at load without controller: rise time equal  216.319ms , overshoot equal  58.654% and undershoot equal 0.210%.3rd  at no load with PID controller: rise time equal  1.177s , overshoot equal  0.505% and undershoot equal 1.914%.4th   at load with PID controller: rise time equal  1.112s , overshoot equal  0.509% and undershoot equal 5.856%

Design & Implementation of Motion Controller for Industrial Paper Cutting Machine

In order to solve a speed control, Speed measurement & synchronization problem, an effective motion controller is design & develop for paper cutting machine of papermaking plant. PID control algorithm was proposed to solve the problem in this paper. The speed closed-loop control was realized after studying & comparing different control algorithm. According to comparison of industrial application results, the applied control strategy to develop a motion controller truly guide, control & can accurately restrain the load disturbance and improve the control effect of synchronization for the cutter speed. This System proves how it can be a low cost solution in the production practice

An Application of Symmetrical Optimum Method to Servo Systems with Variable Inertia

The paper presents an application of the Symmetrical Optimum method under the form of the Extended Symmetrical Optimum method to the design of controllers for servo systems with variable inertia. A brushless direct current servo system with variable inertia is considered as the plant. A proportional-integral controller is tuned for the speed control of this plant using the Extended Symmetrical Optimum method. The results are shown for four values of the moment of inertia and two variable reference input shapes

Development and performance evaluation of servo based PLC operated grain automatic weigher for Flour mill industry

Weigher is the necessity of a flour mill either to weigh the clean wheat before 1st break rolls or to weigh the final products to calculate extraction rate.  Low cost automatic weighing machine using latest technology of servo control and Programmable Logic Control was developed considering the advantages of electronic weighing and linear motion guide ways moving accuracies.  Statistical analysis indicated that there was no significant difference in mean value of measurements from set mass (1500, 3500, 5000g) and measured mass at the 95% probability level.  Minimum average percentage error (< 0.2%) was observed for 3500 to 5000g weight measurements.  Mass measurements on the dispensed material under repeatability conditions produced results within ± 0.22% of displayed set mass for 3000 to 5000g and     revealed that mass measurement of product by auto grain weigher was quite precise.  Automatic weigher can be used for mass measurement of granular products in automated production processes. Keywords: Wheat, Weigher, Servo, PLC, Ballscrew, Loadcel

DEVELOPMENT & PERFORMANCE EVALUATION OF HYBRID NN – PID CONTROLLER FOR DC SERVOMOTOR

The project focuses on position control of the DC Servo Motor MS150 Servomotor Modular. The objectives of the project is to design and develop an advanced control strategy for the use in the servomotor as well as to observe, evaluate and compare the controller performances of a proposed advanced controller – Artificial Neural Network (ANN) with the conventional controller that is Proportional – Integral – Derivative (PID) Control. This approach is selected to investigate and evaluate the conventional method in controlling the position of DC servomotor due to the advantage of cost reduction, simplicity, flexibility and also provides better performance. Based on the information obtained from servomotor modular, the controllers are designed and simulated using MATLAB/SIMULINK to analyze their initial performance. Finally, the performance of the controllers are compared and evaluated and the validation is done in terms of time response, overshoot response and steady – state error