BICYCLE ICYCLE TRAINERRAINER

Transcription

1 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» EMR AND INVERSION-BASED CONTROL OF A VIRTUAL IRTUAL REALITY EALITY BICYCLE ICYCLE TRAINERRAINER M-A. Leblanc Pierre Sicard Université du Québec à Trois-Rivières, Canada

2 Introduction 2 Let the cyclist feel the road when he wasn t there! In virtual reality training, we want the cyclist to feel the same effects on a stationary bike as he would on the road. The virtual reality training system consists of a bicycle trainer base, a data base from a virtual or real road ride and an electrical drive for loading and energy recovery. The EMR is use to clarify the representation of various models used for the environment, cyclist force estimation and control design.

3 Contents 3 1/ Problem statement 2/ EMR modeling of the dynamic braking system 3/ Reference signal for emulation 4/ Inversion-based control 5/ Results 6/ Conclusion

4 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» PROBLEM STATEMENT

5 Problem statement The cyclist should feel effects from: Mass Inertia Slope Aerodynamics Wheel-road friction 5

6 Problem statement The behaviour of the virtual trainer should be independent of the bicycle being used and how it is being used: we shall consider a model at the interface between the wheels and the road. 6

7 Problem statement 7 A passive braking system may be used, with some restrictions. To provide greater opportunities for virtual training and for educational purposes, an active loading system will be used, providing capabilities to use the produced energy or to connect the trainer to a power network.

8 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» EMR MODELING OF THE DYNAMIC BRAKING SYSTEM

9 EMR modeling of the dynamic braking system 9 A dc machine (generator) is used for loading the bicycle. The bicycle is coupled to the generator through a simple transmission (roller).

10 EMR modeling of the dynamic braking system 10 Power converters are used to control the load and to interface the trainer to an electric load or a power network.

11 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» REFERENCE SIGNAL IGNAL FOR EMULATION

12 Reference signal for emulation We want to choose a control structure and measurements so that the virtual trainer reproduces the effects of the environment and cyclist (mass, aerodynamics ). 12

13 Reference signal for emulation What should be the reference input for emulation? 13 Load force as a reference input: An apparent natural choice to impose aerodynamic and gravity effects. Inclusion of mass-inertia effect in the reference signal would require time derivation of measured speed (or acceleration measurement). Bicycle velocity as a reference input: Maintaining the velocity in the trainer close to the model velocity, with high dynamics, implies proper loading. The reference velocity is obtained directly from the cyclistenvironment model. This option is chosen.

14 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» INVERSION-BASED CONTROL

15 Inversion-based control 15 At this point, we assume that the applied force is measured. The environment model reproduces the real system with the cyclist s and bicycle mass-inertia, aerodynamics, friction and slope along a predefined trajectory. In the following, we will only consider the load emulation control and assume that the dc-bus voltage is well controlled.

16 Inversion-based control 16 Using inversion-based control we deduce the control structure To obtain a practical control structure: Neglect electromotive force E Roller torque can be estimated from applied force (Force) Applied force can also be estimated or observed to avoid using expensive sensors.

17 Inversion-based control 17 Applied force estimation is obtained by using the models of the bike trainer and machine. Only classical measurements are required, i.e. current and machine speed.

18 Inversion-based control 18

19 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» RESULTS

20 Results 20 Simulation results were obtained with Simulink TM for the emulation system using data from the experimental system under development. Step response of the force estimator Characteristics of applied force profile: low frequency cyclic force. Applied force Estimated force Time

21 Results Simulation responses to a variation of slope and to a variation of applied force: applied force is estimated accurately velocity of the trainer tracks the emulation model velocity. 21 Desired velocity Simulated velocity Applied force Estimated force Time

22 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» CONCLUSION EMR provides a convenient and useful framework to describe and to define inverse-based control of electromechanical systems. EMR proved very useful to clarify the control problem and to select a control strategy, including a convenient and efficient way to generate the reference input and to define a partial state observer. A relatively complex system, including its control, can be explained simply to non experts.

23 Workshop EMR 09 Trois-Rivières September Application: 2009 «Modelling and control using Energetic Macroscopic Representation» CONCLUSION The virtual reality bicycle trainer is under development. It will be used for undergraduate and graduate level training and for demonstration purposes.

24 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» CONCLUSION Energy management issues : The dc-bus voltage can be maintained to the desired value only if power balance is achieved: External load or a braking resistor must dissipate the produced energy to avoid overvoltage; If produced power is smaller than losses, dc-bus voltage cannot be maintained unless energy storage or a connection to the power grid is used; Without energy storage or a connection to the power grid, loads that require a stable or fixed voltage cannot be fed by this system; Energy storage or a connection to the power grid, and a bidirectional power converter to interface the dc-machine, are required to reproduce coasting and going downhill conditions. These issues are considered in implementation and for future work.

25 Workshop EMR 09 Trois-Rivières September 2009 «Modelling and control using Energetic Macroscopic Representation» REFERENCES M-A. Leblanc, Émulation de charge (Projet Vélo),Rapport de projet d activités de synthèse en génie électrique, Département de génie électrique et génie informatique, Université du Québec à Trois-Rivières, Mai M-A. Leblanc, Conception et mise en oeuvre d un système d entraînement virtuel pour cyclistes,rapport de stage en génie électrique, Département de génie électrique et génie informatique, Université du Québec à Trois-Rivières, Septembre Seabury et al., Ergonomics, 1977, 20, pages :