Adaptive Tuning System Research Articles

Interacting Multiple Model Adaptive Unscented Kalman Filter for Accurate Localization of a High-Dynamic Motion Mobile Robot Using Wireless Sensor Network

Accurate and precise positioning of a mobile robot is a critical problem in the navigation system, and it has become difficult for localization indoors and in GPS-denied areas. Odometry, which is based on dead reckoning, cannot usually provide long-term accurate position estimates. As a result, integrating encoder-based odometry with Wireless Sensor Network (WSN) measurements is recommended as a good solution for minimizing divergences due to uncertainties. The Kalman filtering technique is used to improve state estimation and measurement fusion. Therefore, this paper describes the design and implementation of an Unscented Kalman Filter (UKF) with an adaptive tuning technique to adjust the process noise covariance matrix, resulting in better position estimation, particularly in high-dynamic motions of the mobile robot. Furthermore, for a mobile robot, this work proposes an Interacting Multiple Model (IMM) method with two dynamic motion models, i.e. Constant Velocity (CV) and Coordinated Turn (CT), to deliver high performance with minimal computational overhead. Several experiments on two types of mobile robots were conducted to evaluate and compare the effectiveness of the proposed localization algorithm. The proposed localization technique outperformed the other three methods and demonstrated its effectiveness in high dynamic motions due to the adaptive tuning system.

An Adaptive Parameter Tuning Method with On-Machine Weight Identification Function for CNC Machine Tools

Different inertia effect causes different control errors. To have an optimal control performance, the control parameters of a CNC machine tool should be adaptively tuned based on the variation of the weight of the workpiece in machining process. In this study, simulation based on a theoretical model was made to investigate the influence of inertial effect and friction force on the servo accuracy of a CNC machine tool’s. By using empirical method, an adaptive tuning system that can auto-tune the CNC control parameters based on the detected weight of workpiece was developed. An on-machine weight identification system that can on-machine identify the weight of the workpiece was developed. After integrating the two systems, a control parameter tuning system which can be implanted into CNC controller was developed with the macro executor. Experimental results have shown that the system can effectively improve the accuracy of a machine tool through adaptively tuning control parameters based on the current weight of the machined.

High speed and silicon-saving adaptive tuning system for high frequency Gm-C filters

In this paper, a novel adaptive tuning system used in Gm-C continuous time (CT) filters has been presented. The novelty of this method is the generation of quasi-gradient functions for the adaptive algorithm. By this method we have implemented the fully adaptive tuning algorithm on chip, and received more than 95% precision for the all characteristics of Gm-C filter. All the circuit level simulations and prototype fabrication have been done using 0.6 μ CMOS technology of AMS.

Adaptive Tuning of Switched-Mode Power Supplies Operating in Discontinuous and Continuous Conduction Modes

This paper presents an approach to adaptive tuning of voltage-mode digital controllers for switched-mode power supplies in the presence of large signal changes from discontinuous conduction mode (DCM) to continuous conduction mode (CCM) and vice versa. The approach is capable of maintaining a high-performance control loop without the stability issues related to DCM-to-CCM mode transitions. The adaptive tuner, modeled as a multiple-input-multiple-output (MIMO) controller, is designed to continuously adjust the parameters of a PID compensator such that crossover frequency and phase margin measured by the digital controller match desired values. A simplified design procedure for the adaptive tuning system is proposed that reduces the small-signal MIMO design into two independent single-input, single-output control loops. Simulation results are given showing that despite wide uncertainty in the power stage, the adaptive tuning system still converges to the desired stability margins. Experimental results are given using an 11- to 5-V, 45-W, DCM/CCM buck converter as a test bed.

Design and Implementation of an Adaptive Tuning System Based on Desired Phase Margin for Digitally Controlled DC–DC Converters

This letter presents an online adaptive tuning technique for digitally controlled switched-mode power supplies (SMPS). The approach is based on continuous monitoring of the system crossover frequency and phase margin, followed by a multi-input-multi-output (MIMO) control loop that continuously and concurrently tunes the compensator parameters to meet crossover frequency and phase margin targets. Continuous stability margin monitoring is achieved by injecting a small digital square-wave signal between the digital compensator and the digital pulsewidth modulator. The MIMO loop adaptively adjusts the compensator parameters to minimize the error between the desired and measured crossover frequency and phase margin. Small-signal models are derived, and the MIMO control loop is designed to achieve stability and performance over a wide range of operating conditions. Using modest hardware resources, the proposed approach enables adaptive tuning during normal SMPS operation. Experimental results demonstrating system functionality are presented for a synchronous buck SMPS.

Tuning of continuous-time filters in the presence of parasitic poles

The parasitic effects and tuning limitations that nonideal integrators have on continuous-time filters are discussed. The nonideal integrator is modeled to have finite DC gain and a single nondominant pole. The performance of an adaptive tuning system on tuning a continuous-time filter with nonideal integrators is compared to that of the popular approach of tuning only the poles of a transfer function. Simulation results are presented showing that the adaptive tuning system significantly reduces parasitic effects.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Automatic tuning of continuous-time integrated filters using an adaptive filter technique

An adaptive filter technique for tuning continuous-time integrated filters is presented. This technique is based on the model-matching configuration and tunes both the poles and zeros of the transfer function. Circuit details of an experimental prototype are given. The experimental prototype consists of an integrated third-order filter that is automatically tuned by off-chip circuitry realizing the adaptive tuning system. Both experimental and simulation results are presented to confirm the viability of the proposed approach.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>