Systems, devices, and methods for providing actuator braking
Systems, methods, and devices for control of actuators are provided. In aspects, the systems, methods, and devices provided herein enable the generation of sharp cutoff haptic effects of both limited and extended duration. The systems, methods, and devices use open loop braking signals to generate the sharp cutoff haptic effects. The braking signals are determined based on predictions of system response made according to driving signals used to cause the haptic effects in the actuators. Numerous other aspects are provided.
1. A haptically enabled device, comprising:
an actuator;
a control circuit configured to control the actuator to produce a haptic effect by:
providing a driving signal associated with an amplitude, a frequency, and a number of peaks or a number of oscillation half-cycles to the actuator;
providing a first braking signal having a first braking signal duration based on the frequency associated with the driving signal; and
providing to the actuator a second braking signal having at least one of a second braking signal duration based on the frequency associated with the driving signal and a start time based on the frequency and the number of peaks or the number of oscillation half-cycles associated with the driving signal.
2. The haptically enabled device of claim 1 , wherein the first braking signal duration is further based on a first braking signal safety factor.
3. The haptically enabled device of claim 1 , wherein the first braking signal safety factor is selected such that the result of the haptic effect caused by the driving signal is reduced below a haptic perceptibility threshold in a time interval equal to less than one period of the driving signal.
4. The haptically enabled device of claim 1 , wherein the start time of the second braking signal is further based on at least one of the amplitudes associated with the driving signal and a second braking signal safety factor.
5. The haptically enabled device of claim 1 , wherein the second braking signal safety factor is selected such that the result of the haptic effect caused by the driving signal is reduced below a haptic perceptibility threshold in a time interval equal to less than one period of the driving signal.
6. The haptically enabled device of claim 1 , wherein the control circuit is further configured to control the actuator to produce the haptic effect by determining the first braking signal and determining the second braking signal before providing the first driving signal to the actuator.
7. The haptically enabled device of claim 1 , wherein the first braking signal duration is further based on a first braking signal safety factor; and
the start time of the second braking signal is further based on a second braking signal delay factor.
8. The haptically enabled device of claim 1 , wherein the first braking signal safety factor and the second braking signal safety factor are selected such that the result of the haptic effect caused by the driving signal is reduced below a haptic perceptibility threshold in a time interval equal to less than one period of the driving signal.
9. The haptically enabled device of claim 1 , further comprising determining a duration of the second braking signal according to a comparison of input energy to the actuator provided by the driving signal and energy removed from the actuator by the first braking signal.
10. The haptically enabled device of claim 1 , wherein the first braking signal is provided in opposition to a velocity of the actuator.
11. A method of controlling an actuator to produce a haptic effect comprising:
providing a driving signal associated with an amplitude, a frequency and a number of peaks or a number of oscillation half-cycles to the actuator;
providing to the actuator a first braking signal having a first braking signal duration based on the frequency associated with the driving signal;
providing to the actuator a second braking signal having at least one of a second braking signal duration based on the frequency associated with the driving signal and a start time based on the frequency and the number of peaks or the number of oscillation half-cycles associated with the driving signal.
12. The method of claim 11 , wherein the first braking signal duration is further based on a first braking signal safety factor.
13. The method of claim 12 , wherein the first braking signal safety factor is selected such that the result of the haptic effect caused by the driving signal is reduced below a haptic perceptibility threshold in a time interval equal to less than one period of the driving signal.
14. The method of claim 11 , wherein the start time of the second braking signal is further based on at least one of the amplitude associated with the driving signal and a second braking signal safety factor.
15. The method of claim 14 , wherein the second braking signal safety factor is selected such that the result of the haptic effect caused by the driving signal is reduced below a haptic perceptibility threshold in a time interval equal to less than one period of the driving signal.
16. The method of claim 11 , further comprising determining the first braking signal and determining the second braking signal before providing the first driving signal to the actuator.
17. The method of claim 11 , wherein:
the first braking signal duration is further based on a first braking signal safety factor; and
the start time of the second braking signal is further based on a second braking signal delay factor.
18. The method of claim 17 , wherein the first braking signal safety factor and the second braking signal safety factor are selected such that the result of the haptic effect caused by the driving signal is reduced below a haptic perceptibility threshold in a time interval equal to less than one period of the driving signal.
19. The method of claim 11 , further comprising determining a duration of the second braking signal according to a comparison of input energy to the actuator provided by the driving signal and energy removed from the actuator by the first braking signal.
20. The method of claim 11 ,
wherein the first braking signal is provided in opposition to a velocity of the actuator.