Benedikt Alt

Strong structural controllability of linear systems revisited

Recently, the concept of strong structural controllability has attracted renewed attention. In this context the existing literature to strong structural controllability has been revisited and some of the previous results have been found to be incorrect. Therefore, in this paper an overview of the previous results on strong structural controllability, counter-examples and a new graph-theoretic characterization of strong structural controllability are given.

Self-tuning control design strategy for an electronic throttle with experimental robustness analysis

In this paper a self-tuning control design strategy for the electronic throttle is introduced. The proposed control design consists of a modified PID controller and an additional nonlinear controller that helps to compensate the nonlinearities of the plant. The control parameters are calculated automatically using an appropriate process identification algorithm. The efficiency of the proposed control design strategy is shown by experimental results. In a next step the performance loss due to aging effects is analyzed. Finally, the robustness properties with regards to environmental influences are investigated.

Multiple sliding surface control of idle engine speed and torque reserve with load torque estimation

A novel controller based on multiple sliding surface control is adopted to automotive engine control at idle condition. The control task is to maintain the engine speed and the torque reserve at their reference values despite parameter uncertainties and variations in the intake-to-torque-production delay. Additionally, a disturbance estimator is applied to reconstruct unknown load torque disturbances based on measurements of the engine speed. A validated nonlinear simulation model is used to evaluate the performance of the closed-loop system and it is shown that the system is robust with respect to the mentioned uncertainties and disturbances.

Control of idle engine speed and torque reserve with higher order sliding modes

In this paper a novel framework for idle speed control of a spark ignition engine is introduced. The control task is to maintain the engine speed and the torque reserve at their reference values while the clutch is open. For this purpose a robust control design is proposed using sliding mode theory. It will be shown that this framework is robust against external load torque disturbances, parameter uncertainties and variations in the intake-to-torque-production delay leading to significant changes in the operating conditions of the engine. The performance and the robustness properties of the closedloop system are demonstrated by nonlinear simulation and experimental results.

Multiple Sliding Surface Control of Idle Engine Speed and Torque Reserve With Dead Start Assist Control

The subject of this paper is a multiple sliding surface controller that is adopted to automotive engine control at idle condition. The control task is to hold the engine speed and the torque reserve at their reference values despite parameter uncertainties, variations in the intake-to-torque-production delay, or even in the case of external load torque disturbances. Additionally, the dead start of the vehicle is intensively studied and an appropriate extension of the controller with an internal switching law is developed. A validated nonlinear simulation model is used to evaluate the performance and the robustness of the closed-loop system. Furthermore, experimental results show the effectiveness of the proposed control design.

Multivariable speed synchronisation for a parallel hybrid electric vehicle drivetrain

In this article, a new drivetrain configuration of a parallel hybrid electric vehicle is considered and a novel model-based control design strategy is given. In particular, the control design covers the speed synchronisation task during a restart of the internal combustion engine. The proposed multivariable synchronisation strategy is based on feedforward and decoupled feedback controllers. The performance and the robustness properties of the closed-loop system are illustrated by nonlinear simulation results.

Robust fuzzy cascade control revised: Application to the rotary inverted pendulum

Fuzzy controllers are used in many practical applications since they guarantee impressive robustness properties and the control design requires only simple rules which are based on heuristic knowledge. However, since the number of rules is increased with the number of control inputs and measurements the control design may become overloaded and the design efforts even require more time than with classical approaches. To overcome this drawback this paper revises a comprehensive robust fuzzy cascade control strategy where all controllers are based on a uniform fuzzy set with a minimum number of rules. This approach represents an interesting perspective in education since the individual controllers need to be only calibrated with the scaling on their inputs and outputs. To show the efficiency and the robustness properties of the proposed control framework this fuzzy cascade design method is applied to Quansers rotary inverted pendulum.

Second-order sliding modes control for in-vehicle pedal robots

In this contribution a second-order sliding modes based control design approach for setpoint tracking of an in-vehicle pedal robots position is introduced. For this purpose a novel concept of in-vehicle pedal robots is considered, which is based on a PM-DC drive with rope winch and an optical distance sensor. In the control design task the distance between a brake, clutch or accelerator pedal and the ground of the drivers cab should follow a given reference value. Nonlinear simulation results show the efficiency and the robustness properties of the proposed second-order sliding modes control design approach.

Decoupling control for the speed synchronization task in the powertrain of a hybrid electric vehicle

In this paper a novel framework for a multivariable control design task in the field of hybrid electric vehicles is introduced. The problem under consideration consists of a speed synchronization task of two propulsion aggregates using a controllable separation clutch. During this synchronization period the longitudinal vehicle motion of the vehicle should not be affected. The proposed control strategy is based on a decoupling network and two optimized controllers. The performance and robustness properties of the closed-loop system are shown by nonlinear simulation results.

Flatness based control for electric and hybrid electric vehicle drivetrains

Up to now feedforward controllers are seldomly used for the control of automotive vehicle drivetrains. This is partially due to the fact that this popular approach which is based on the inversion of a nominal model may become rather involved. In this paper we illustrate the simplicity and efficiency of flatness based feedforward controller design for the drivetrains of electric and hybrid electric vehicles.