Yen-Fang Li

H filtering and solution bound for non-linear systems

In this paper, sufficient conditions for the existence of a solution to the non-linear H filtering problem are presented. The conditions are expressed in terms of the solution to a Hamilton-Jacobi inequality involving only n + 1 (for time-varying case) or n (for time-invariant case) independent variables. Both affine and general non-linear systems are examined. In the time-invariant affine non-linear case, one kind of positive radial solution to the Hamilton-Jacobi inequality is presented, and an explicit estimation of the achievable disturbance attenuation level is given. Illustrative examples are also included.

H/sup /spl infin// filtering and solution bound for nonlinear systems

In this paper, sufficient conditions are presented for the existence of a solution to the nonlinear H/sup /spl infin// filtering problem. The conditions are expressed in terms of the solution to a Hamilton-Jacobi inequality involving only n+1 (for time-varying case) or n (for time-invariant case) independent variables. Both affine and general nonlinear systems are examined. In the time-invariant affine nonlinear case, we also present one kind of positive radial solution to the Hamilton-Jacobi inequality, and give an explicit estimation of the achievable disturbance attenuation level.

A new MTPA control strategy for sensorless V/f controlled PMSM drives

This paper presents a new maximum torque per ampere (MTPA) control strategy for sensorless V/f controlled PMSM drives. The proposed theoretical basis can be applied to both surface permanent magnet synchronous motor (SPMSM) and interior permanent magnet synchronous motor (IPMSM) drives to obtain high efficiency. Two closed loops are required in the proposed drive. First, by using the oscillatory active power information, a load angle compensation component is generated to adjust the load angle to stabilize the system. Second, the drive imaginary power is regulated to follow the imaginary power of MTPA performance such that the drive can operate under the minimum copper loss condition in the steady state. The imaginary power controller can generate a voltage compensation component to properly adjust the drive voltage. Hence, the demanded MTPA performance is obtained. The provided simulation results show the performance and validity of the proposed strategy. The hardware implementation of the proposed control is now undertaking and the experimental results will soon be shown in the near publication.

H∞ filtering of nonlinear systems with sampled measurements

Abstract In this paper, the H ∞ filtering problem is studied for nonlinear continuous-time systems with sampled measurements. Sufficient conditions are derived for the existence of filters that satisfy a specified H ∞ performance bound. These conditions are expressed in terms of the solution of a differential Hamilton–Jacobi inequality with jumps. When these conditions hold, state-space formulae are also given for such a filter. A numerical example is included to illustrate the proposed filter design method.

Electronic piano playing robot

In recent years, service robots are widely used for different fields. The fields include house cleaning, entertainment, reception and security. Entertainment has become an important issue for robot applications. In this paper, we design an electronic piano playing robot which can automatically play electronic piano according to a user-defined piano sheet music. The robot has 5 finger hands to play the electronic piano keyboard. There are 2 degrees of freedom in each finger. Stepping motors are employed to rotate finger mechanisms to the desired position. Finger tip are pulled up and down by a steel string with a pneumatic cylinder. A specially-designed controller move the finger tip down to hit the desired key on the electronic piano. If the range of finger movement cannot touch the desired key then the hand will be moved by a linear motor. All fingers and hands can be controlled by the controller independently. Digital I/O PCI card are used to send commands to the controller.

Model reference adaptive control design for the buck-boost converter

In this study, a model reference adaptive digital control scheme is proposed for the buck-boost converter. The control design of the buck-boost converter is a challenging work because the buck-boost converter, which is a non-minimum phase (NMP) system, has a right half-plane zero. This controller design is based on the small signal model of the buck-boost converter and a reference model. A cost function of the output error and weighting control input is minimized for the buck-boost converter using the model reference adaptive control scheme. In the case that the plant parameters are uncertain (or unknown), a digital controller with model reference adaptive control scheme is proposed for the buck-boost converter using the recursive least-squares (RLS) algorithm to estimate the uncertain parameters. To verify the validity of the proposed controller, experimental set-up is built for the buck-boost converter and the fully digital adaptive controller is implemented by a digital signal processor TMS320-F28335. From the experimental results, sound performances on voltage regulation can be achieved for the buck-boost converter with uncertain parameters using the proposed controller.

Intelligent algorithm for music playing robot — Applied to the anthropomorphic piano robot control

Simple and friendly operation interface, intelligent calculation, high performance control and driving circuit, and precision and reliable plant are the necessary conditions for intelligent robot design. In this paper, an intelligent algorithm is proposed for the piano robot control with an interactive program and an automatic control code generator. The interactive program of man-machine interface makes the musical score input is simple and friendly as the piano keyboard playing. This interactive program can identify the musical beat and note automatically while the user plays the keyboard on PC monitor. The interactive program of man-machine interface makes the musical score input is simple as the piano keyboard playing. This program can identify the musical beat and note automatically while the user plays the keyboard on PC monitor and then the musical score is built. The control code generator, an intelligent algorithm, will convert the musical score to generate a series of optimum positions commands accordingly for the hands and fingers of the piano robot to play a piano. The optimum positions commands are programmed with crashing protection and minimum movement for the hands and fingers to anthropomorphize the robot. Via the algorithm operation, the music control codes are generated automatically to replace the situation of manual coding and give the ability of intelligent thinking for the piano robot.

Auto-tuning controller design of class E inverter with resonant components varying

Class E resonant power amplifier (or inverter) is often applied to design a high frequency switching power converter. The zero voltage switching (ZVS) or zero current switching (ZCS) operation leads the converter to high converting efficiency even the converter works at high frequency. Theoretically, with a high speed power transistor, the class E amplifier can work from several megahertzs to dozen of megahertzs. While the resonant components of class E inverter are varying, the ZVS operation will be shifting around the dominant operating point. In this paper, we propose an auto-tuning control method to overcome the components shifting problem. Also, the practical control system is implemented by FPGA module board. The prototypical circuit of 150 W, 1.2 MHz parallel driving Class E systems with full digitized controller has been accomplished to verify the proposed control method and performance.

Exactly analysis of ZVS behavior for class E inverter with resonant components varying

Class E resonant power amplifier (or inverter) is often applied to design a high frequency switching power converter. The zero voltage switching (ZVS) or zero current switching (ZCS) operation leads the converter to high converting efficiency even the converter works at high frequency. Theoretically, with a high speed power transistor, the class E amplifier can work from several megahertzes to dozen of megahertzes. While the resonant components of class E inverter are varying, the ZVS operation will be shifting around the dominant operating point. In this paper, an exact circuit model is proposed to analyze the circuit behavior for the class E inverter. Unnecessarily mathematical assumption and complicated numerical iteration, the proposed model is easy to analyze the class E circuits in frequency domain. Through this model, a close form formula is proposed to solve the load current and drain-source end voltage of MOSFET at switching instants for steady state without a complicated numerical iterating. By this formula, the optimal and suboptimal conditions for the ZVS operation are expressed in terms of the shifting angle of load current with respect to drain-source voltage. Also, some practical design examples are given to demonstrate the formula calculating results that are good agreement with the numerical iterating results.

FPGA-based module design for PM linear motor control-applied to music playing robot

In this paper, a motion control module design is considered for multi actuator control system with parallel control capability. And, the control module is implemented to a music playing robot. This robot control system with parallel controlling of two hands and ten fingers is implemented by a hierarchical control structure, i.e. host controller (PC-based) and local controller (FPGA-based), to achieve the anthropomorphic piano robot control. The host controller is in charge of the whole system integration and the music codes encoding of playing music to command the robot via the target controller. The target controller, or called local controller or distributed control module, actually performs the close loop control task of each actuator while it receives the command code. The palms of the robot are driving by a PM linear motor that consists with two movers in a common track stator and they are controlled by the target controller directly. In this paper, we will focus on the FPGA-based controllers design use a practical technique including the velocity and position control loops design for the anthropomorphic piano robot. With some experiments of hard ware in the loop, the control gain can be calculated easily in S-domain and digitizing to Z-domain for FPGA-based controller implementing. The control modules have been applied to control the anthropomorphic piano robot successfully. The results of experiment have given verification about the practical controller design method and the hierarchical control structure.