Pedal drive system
A pedal drive system, in particular for an electric vehicle or a training apparatus, and for generating electrical power from muscle power of a user with at least one pedal and an electric generator, connected mechanically with said at least one pedal, is provided. To improve the haptic feel and feedback at the pedal, a control unit is provided for controlling a feedback torque, applied at said pedal, wherein the control unit comprises a haptic renderer, configured for control of said feedback torque based on at least one user-defined pedal reference trajectory.
1. A pedal drive system for generating electrical power from muscle power of a user with at least
one pedal;
an electric generator connected mechanically with said at least one pedal; and
a control unit for controlling a feedback torque applied at said pedal; wherein
the control unit comprises a trajectory database, comprising at least one user-defined pedal reference trajectory, and a haptic renderer, configured for control of said feedback torque based on the at least one user-defined pedal reference trajectory; wherein
the at least one user-defined pedal reference trajectory is based on pedaling behavior of the user during prior use of the pedal drive system.
2. The pedal drive system according to claim 1 , further comprising a user trajectory modeler, configured to receive a torque course during use and to generate or update the at least one user-defined pedal reference trajectory based on the torque course.
3. The pedal drive system according to claim 1 , wherein the control unit further comprises an inertia modeler, configured to iteratively adapt the at least one user-defined pedal reference trajectory to obtain at least one adapted user-defined pedal reference trajectory, wherein the at least one adapted user-defined pedal reference trajectory is provided to the haptic renderer for control of said feedback torque.
4. The pedal drive system according to claim 3 , further comprising a user trajectory modeler, configured to receive the adapted pedal reference trajectory and to generate or update the at least one user-defined pedal reference trajectory based on a received past torque course.
5. The pedal drive system according to claim 1 , wherein the at least one user-defined pedal reference trajectory corresponds to a pedal cadence reference trajectory.
6. The pedal drive system according to claim 1 , wherein the haptic renderer is configured for impedance control of said feedback torque so that movement of the pedal is adapted to the at least one user-defined pedal reference trajectory.
7. The pedal drive system according to claim 3 , wherein the inertia modeler is configured to adapt the at least one user-defined reference trajectory based on at least one trajectory parameter.
8. The pedal drive system according to claim 3 , wherein the inertia modeler is configured to:
determine a past torque course for a predefined sampling time,
determine a reference torque course, corresponding to the at least one user-defined reference trajectory, for said predefined sampling time using a vehicle model,
conduct a comparison of the past torque course with the reference torque course, and to
determine at least one adapted user-defined pedal reference trajectory based on said comparison.
9. The pedal drive system according to claim 1 , wherein the control unit comprises multiple different pedal reference trajectories.
10. The pedal drive system according to claim 1 , wherein said haptic renderer is configured to select one of said multiple reference trajectories automatically based on a trajectory selection signal.
11. The pedal drive system according to claim 3 , wherein said inertia modeler is configured to iteratively adapt the at least one user-defined pedal reference trajectory at predetermined intervals which correspond to less than one revolution of said pedal, in particular at most 10 degrees, at most 5 degrees or at most 3 degrees of rotation angle of said pedal.
12. An electric vehicle with a pedal drive system according claim 1 , comprising an electronic transmission connecting said generator to an electric load, and/or an electric drive motor.
13. A training apparatus with a pedal drive system for generating electrical power from muscle power of a user with at least
one pedal;
an electric generator; connected mechanically with said at least one pedal; and
a control unit for controlling a feedback torque; applied at said pedal; wherein
the control unit comprises a trajectory database, comprising at least one user-defined pedal reference trajectory, and a haptic renderer, configured for control of said feedback torque based on the at least one user-defined pedal reference trajectory.
14. A method of operating a pedal drive system for generating electrical power from muscle power of a user with at least one pedal and an electric generator, connected mechanically with said at least one pedal, comprising:
controlling a feedback torque, applied at said pedal, based on at least one user-defined pedal reference trajectory; wherein the at least one user-defined pedal reference trajectory is based on pedaling behavior of the user during prior use of the pedal drive system.
15. A pedal drive system for generating electrical power from muscle power of a user with at least
one pedal;
an electric generator connected mechanically with said at least one pedal; and
a control unit for controlling a feedback torque applied at said pedal; wherein
the control unit comprises a trajectory database, comprising at least one user-defined pedal reference trajectory, and a haptic renderer, configured for control of said feedback torque based on the at least one user-defined pedal reference trajectory; wherein
the control unit further comprises an inertia modeler, configured to iteratively adapt the at least one user-defined pedal reference trajectory to obtain at least one adapted user-defined pedal reference trajectory, wherein the at least one adapted user-defined pedal reference trajectory is provided to the haptic renderer for control of said feedback torque.
16. The pedal drive system according to claim 15 , further comprising a user trajectory modeler, configured to receive the adapted pedal reference trajectory and to generate or update the at least one user-defined pedal reference trajectory based on a received past torque course.
17. The pedal drive system according to claim 15 , wherein the inertia modeler is configured to adapt the at least one user-defined reference trajectory based on at least one trajectory parameter.
18. The pedal drive system according to claim 15 , wherein the inertia modeler is configured to:
determine a past torque course for a predefined sampling time,
determine a reference torque course, corresponding to the at least one user-defined reference trajectory, for said predefined sampling time using a vehicle model,
conduct a comparison of the past torque course with the reference torque course, and to
determine at least one adapted user-defined pedal reference trajectory based on said comparison.
19. The pedal drive system according to claim 15 , wherein said inertia modeler is configured to iteratively adapt the at least one user-defined pedal reference trajectory at predetermined intervals which correspond to less than one revolution of said pedal, in particular at most 10 degrees, at most 5 degrees or at most 3 degrees of rotation angle of said pedal.
20. An electric vehicle with a pedal drive system according claim 15 , comprising an electronic transmission connecting said generator to an electric load, and/or an electric drive motor.
21. A method of operating a pedal drive system for generating electrical power from muscle power of a user with at least one pedal and an electric generator, connected mechanically with said at least one pedal, comprising:
controlling a feedback torque, applied at said pedal, based on at least one user-defined pedal reference trajectory; and
iteratively adapting the at least one user-defined pedal reference trajectory to obtain at least one adapted user-defined pedal reference trajectory.