Thomas Schulte

Model-based control for ultrasonic motors

A complete model-based control for traveling-wave-type ultrasonic motors is presented. The control scheme consists of inner control loops with respect to the oscillation systems, offering all meaningful degrees of freedom for adjusting the traveling bending wave, and outer control loops for torque and speed. After a brief review on modeling the actuator and presentation of a parameter identification method, the control scheme is developed and verified by measurements on a prototype drive system, several measures for the compensation of nonlinearities and temperature effects are developed, and achieved improvements are discussed with respect to the special properties of this novel actuator. Finally, the developed drive is applied to an active control stick.

Real-time HIL-simulation of power electronics

In modern vehicles, electrical drives and power electronics are used to control a large variety of different applications. To operate these components electronic control units have to be designed and tested. To validate the software of the electronic control units hardware-in-the-loop simulation is a todaypsilas standard method. Hardware-in-the-loop simulation always comprises a real-time simulation of the plant, including actuator and sensor models. In case of an electronic circuit the plant consists of passive components like capacitors and inductors, usually assumed to be linear, and semi-conductors with nonlinear and discontinuous behavior. The following paper suggests classification criteria and compares different methods for real-time simulations of electronic circuits considering switching events. For evaluation theoretical considerations as well as simulation results are presented concerning differences in approaches.

Hardware-in-the-Loop Test Systems for Electric Motors in Advanced Powertrain Applications

Electric drives are growing in importance in automotive applications, especially in hybrid electric vehicles (HEV) and in the vehicle dynamics area (steering systems, etc.). The challenges of real-time hardware-in-the-loop (HIL) simulation and testing of electric drives are addressed in this paper. In general, three different interface levels between the electric drive and the hardware-inthe-loop system can be distinguished: the signal level (1), the electrical level (2) and the mechanical level (3). These interface levels, as well as modeling and I/Orelated aspects of electric drives and power electronics devices, are discussed in detail in the paper. Finally, different solutions based on dSPACE simulator technology are presented, for both hybrid vehicle and steering applications.

Real-time simulation of BLDC motors for hardware-in-the-loop applications incorporating sensorless control

This paper presents a hardware-in-the-loop simulation system for simulating BLDC motors. The test bench combines two key technologies; first an electric motor simulation on the electric interface level, which is not only based on control signals but also emulates real currents and voltages; secondly an FPGA-based (field-programmable gate array) electric motor model. The overall simulation concept represents a comprehensive simulation of the electric motor, which is therefore suitable for running controllers incorporating sensorless motor control. Thus it enables integrated hardware-in-the-loop testing for control units which could formerly only be tested by means of mechanical test benches.

High performance speed control for ultrasonic motors

A novel speed control for traveling wave type ultrasonic motors is presented and verified by measurements on a prototype drive, Based on an underlying bending wave control the nonlinear torque generation of the USM is compensated by an inverse contact model calculating the reference values of bending wave control under consideration of an optimized set point adjustment. For this task a basis function neural network is applied. By compensation of the nonlinearity the command behavior of the USM approaches that of conventional drives and proven speed control schemes can be implemented as further control loop, The novel speed control investigated offers excellent dynamic responses and is thus attractive for applications in the field of high performance servo systems.

Real-Time Simulation of Electric Drives by Electronic Load-Emulation

Abstract Using electric motors for complex and increasingly safety-critical functions in vehicles requires comprehensive testing to be performed during system development. This applies above all to the innovative drive concepts used in hybrid and electrical vehicles. Hardware-in-the-loop simulation has become a standard method for testing the software functions for these. There are various interfaces that are suitable for connecting the electronic control unit to the hardware-in-the-loop simulator for systems with electric drives. Test systems that reproduce the physical electrical signals (currents and voltages) at the ECU connectors are also increasingly required. This paper presents several concepts for simulating electric drives by means of electronic load emulation. Particular attention is paid to simulating highpower (> 10 kW) and high-voltage (> 100 V) electric drives.