A resolver-to-digital conversion method based on third-order rational fraction polynomial approximation for PMSM control

—In this paper, a cost-effective and highly accurate resolver-to-digital conversion (RDC) method is presented. The core of the idea is to apply a third-order rational fraction polynomial approximation (TRFPA) for the conversion of sinusoidal signals into the pseudo linear signals, which are extended to the range 0-360° in four quadrants. Then, the polynomial least squares method (PLSM) is used to achieve compensation to acquire the final angles. The presented method shows better performance in terms of accuracy and rapidity compared with the commercial available techniques in simulation results. This paper describes the implementation details of the proposed method and the way to incorporate it in digital signal processor (DSP) based permanent magnet synchronous motor (PMSM) drive system. Experimental tests under different conditions are carried out to verify the effectiveness for the proposed method. The obtained maximum error is about 0.0014° over 0-360° , which can usually be ignored in most industrial applications. Index Terms—Arc tangent function, Analog processing circuits, Pseudo linear signals, Resolver-to-digital conversion (RDC), Third-order rational fraction polynomial approximation (TRFPA)

A resolver-to-digital conversion method based on third-order rational fraction polynomial approximation for PMSM control

In this paper, a cost-effective and highly accurate resolver-to-digital conversion (RDC) method is presented. The core of the idea is to apply a third-order rational fraction polynomial approximation (TRFPA) for the conversion of sinusoidal signals into the pseudo linear signals, which are extended to the range 0-360° in four quadrants. Then, the polynomial least squares method (PLSM) is used to achieve compensation to acquire the final angles. The presented method shows better performance in terms of accuracy and rapidity compared with the commercial available techniques in simulation results. This paper describes the implementation details of the proposed method and the way to incorporate it in digital signal processor (DSP) based permanent magnet synchronous motor (PMSM) drive system. Experimental tests under different conditions are carried out to verify the effectiveness for the proposed method. The obtained maximum error is about 0.0014° over 0-360°, which can usually be ignored in most industrial application

Force sensing enhancement of robot system

At present there is a general industrial need to improve robot performance. Force feedback, which involves sensing and actuation, is one means of improving the relative position between the workpiece and the end-effector. In this research work various causes of errors and poor robot performance are identified. Several methods of improving the performance of robotic systems are discussed. As a result of this research, a system was developed which is interposed between the wrist and the gripper of the manipulator. This system integrates a force sensor with a micro-manipulator, via an electronic control unit, with a micro-computer to enhance a robot system. The force sensor, the micromanipulator and the electronic control unit, were all designed and manufactured at the robotic centre of Middlesex Polytechnic. The force feedback is provided by means of strain gauges and the associated bridge circuitry. Control algorithms which define the relationship between the force detected and the motion required are implemented in the software. The software is capable of performing two specific tasks in real time, these are: 1- Inserting a peg into a hole 2- Following an unknown geometric path A rig was designed and manufactured to enable the robot to follow different geometric shapes and paths in which force control was achieved mainly by control of the micro-manipulator

Modelling and Control of Switched Reluctance Machines

Today, switched reluctance machines (SRMs) play an increasingly important role in various sectors due to advantages such as robustness, simplicity of construction, low cost, insensitivity to high temperatures, and high fault tolerance. They are frequently used in fields such as aeronautics, electric and hybrid vehicles, and wind power generation. This book is a comprehensive resource on the design, modeling, and control of SRMs with methods that demonstrate their good performance as motors and generators

Modelling and Control of Switched Reluctance Machines

Today, switched reluctance machines (SRMs) play an increasingly important role in various sectors due to advantages such as robustness, simplicity of construction, low cost, insensitivity to high temperatures, and high fault tolerance. They are frequently used in fields such as aeronautics, electric and hybrid vehicles, and wind power generation. This book is a comprehensive resource on the design, modeling, and control of SRMs with methods that demonstrate their good performance as motors and generators

Modelling and Control of Switched Reluctance Machines

Today, switched reluctance machines (SRMs) play an increasingly important role in various sectors due to advantages such as robustness, simplicity of construction, low cost, insensitivity to high temperatures, and high fault tolerance. They are frequently used in fields such as aeronautics, electric and hybrid vehicles, and wind power generation. This book is a comprehensive resource on the design, modeling, and control of SRMs with methods that demonstrate their good performance as motors and generators

A precise converter for resolvers and sinusoidal encoders based on a novel ratiometric technique

Resolvers and other sinusoidal encoders provide electrical signals related to the sine and cosine of the unknown angular position of their rotor shafts. Conventional tangent/cotangent converter used with these transducers for determining the angular position is based on the computation of the ratio between the smallest and largest absolute values of the sine and cosine signals. This produces highly non-linear segments of tangent and cotangent requiring large-size look-up tables for the determination of the unknown angle. In this work, a novel method is presented for implementing this technique without the need for the determination of the absolute values of the sensor signals and of the cotangent. Additionally the precision of the proposed technique is guaranteed even by using a small size look-up table or a simple linear computation. The method is based on computing the ratio of sine and cosine segments of a number of phase-shifted sine and cosine signals such that non-linearity of the resulting tangent is greatly reduced due to the limitation of the angle interval in which it needs to be computed. The paper describes full details of the proposed method and provides a comparison with previously-reported techniques through extensive computer simulation. 2016 IEEE.Scopu

39th Aerospace Mechanisms Symposium

The Aerospace Mechanisms Symposium (AMS) provides a unique forum for those active in the design, production, and use of aerospace mechanisms. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms. Organized by the Mechanisms Education Association, NASA Marshall Space Flight Center (MSFC) and Lockheed Martin Space Systems Company (LMSSC) share the responsibility for hosting the AMS. Now in its 39th symposium, the AMS continues to be well attended, attracting participants from both the United States and abroad. The 39th AMS was held in Huntsville, Alabama, May 7-9, 2008. During these 3 days, 34 papers were presented. Topics included gimbals and positioning mechanisms, tribology, actuators, deployment mechanisms, release mechanisms, and sensors. Hardware displays during the supplier exhibit gave attendees an opportunity to meet with developers of current and future mechanism components