Closed-loop motor control using unidirectional data feedback
Systems, methods, and computer-readable media are disclosed for closed-loop control of a motor in a LIDAR system over a wireless power interface using data feedback over a unidirectional data communications interface. An example method may include receiving, by a controller on a first portion in a LIDAR system, from a second portion including a second motor, and over a unidirectional data communication interface, data associated with the second motor, wherein the second portion is configured to rotate relative to the first portion. An example method may also include providing, over a wireless power transfer interface, to the second portion, and based on the data, a power signal, wherein the power signal is used to provide power to the second motor.
1. A LIDAR system comprising:
a first portion including a controller, the controller including a processor;
a second portion including a motor, wherein the second portion rotates relative to the first portion, and wherein the first portion and second portion are separated by a non-contact interface;
a wireless power transfer interface between the first portion and the second portion that provides a power signal in a downstream direction from the first portion to the second portion, wherein the power signal is used to adjust a speed of the motor; and
a unidirectional data communication interface between the first portion and the second portion that provides upstream data indicative of the speed of the motor and a position of the motor to the controller, wherein the upstream data is encoded to remove data indicative of a direction of rotation of the motor,
wherein if the data indicative of the direction of rotation of the motor is variable, the controller is configured to generate the data indicative of the direction of rotation of the motor based on the data indicative of the position of the motor included in the upstream data.
2. A LIDAR system comprising:
a first portion including a controller, the controller including a processor;
a second portion including a motor, wherein the second portion rotates relative to the first portion, and wherein the first portion and second portion are separated by a non-contact interface;
a wireless power transfer interface between the first portion and the second portion that provides a power signal in a downstream direction from the first portion to the second portion, wherein the power signal is used to adjust a speed of the motor; and
a unidirectional data communication interface between the first portion and the second portion that provides upstream data indicative of the speed of the motor and a position of the motor to the controller, wherein the upstream data is encoded to remove data indicative of a direction of rotation of the motor,
wherein the upstream data comprises data indicative of the speed of the motor superimposed with data indicative of the position of the motor to form a ternary signal that is provided to the controller, and
wherein the data indicative of the direction of rotation of the motor is removed from the encoded upstream data if known by previous upstream data.
3. The LIDAR system of claim 1 , wherein the upstream data comprises data captured using a first optical encoder associated with the second portion.
4. The LIDAR system of claim 1 , wherein the unidirectional data communication interface comprises an optical data interface, wherein the optical data interface comprises a light emitting diode (LED) at the second portion and a photodetector at the first portion, the photodetector including two input interfaces.
5. The LIDAR system of claim 1 , wherein the second portion comprises a first structural component and a second structural component, wherein the first structural component rotates relative to the second structural component, and wherein the second structural component further comprises a second optical encoder.
6. The LIDAR system of claim 1 , wherein the encoded upstream data includes a first square wave and a first pulse, wherein the square wave provides information for the motor and the pulse provides information indicative of the position of the motor.
7. The LIDAR system of claim 6 , wherein the square wave is a first high value at a first time and the pulse is a second high value at a second time, and wherein the first high value is different than the second high value.
8. The LIDAR system of claim 1 , wherein the second portion further includes a motor driver that receives the power signal over the wireless power transfer interface, and provides a power level to the motor based on the power signal, wherein the power signal is at least one of: an analog voltage or a pulse-width modulation (PWM) signal.
9. A controller comprising:
a computer processor operable to execute a set of computer-readable instructions; and
a memory operable to store the set of computer-readable instructions operable to:
receive, at a first portion of a LIDAR system, from a second portion of the LIDA system that includes a motor, via a unidirectional data communication interface, upstream data indicative of a speed of the motor and a position of the motor that is encoded to remove data indicative of a direction of rotation of the motor, wherein if the data indicative of the direction of rotation of the motor is variable, the controller is configured to generate the data indicative of the direction of rotation of the motor based on the data indicative of the position of the motor included in the upstream data and wherein the second portion rotates relative to the first portion; and
provide, over a wireless power transfer interface, to the second portion, and based on the encoded upstream data, a power signal used to adjust the speed of the motor.
10. A controller comprising:
a computer processor operable to execute a set of computer-readable instructions; and
a memory operable to store the set of computer-readable instructions operable to:
receive, at a first portion of a LIDAR system, from a second portion of the LIDA system that includes a motor, via a unidirectional data communication interface, upstream data indicative of a speed of the motor and a position of the motor that is encoded to remove data indicative of a direction of rotation of the motor and wherein the second portion rotates relative to the first portion;
superimpose data indicative of the speed of the motor with data indicative of the position of the motor to form a ternary signal, and
wherein the data indicative of the direction of rotation of the motor is removed from the encoded upstream data if known by previous upstream data; and
provide, over a wireless power transfer interface, to the second portion, and based on the encoded upstream data, a power signal used to adjust the speed of the motor.
11. The controller of claim 9 , wherein the upstream data is captured using a first optical encoder associated with the second portion.
12. The controller of claim 9 , wherein the unidirectional data communication interface comprises an optical data interface, wherein the optical data interface comprises a light emitting diode (LED) at the second portion and a photodetector at the first portion that comprises two input interfaces.
13. The controller of claim 12 , wherein the second portion comprises a first structural component and a second structural component, wherein the first structural component rotates relative to the second structural component, and wherein the second structural component further comprises a second optical encoder.
14. The controller of claim 9 , wherein the encoded upstream data includes a first square wave and a first pulse, wherein the square wave provides information for the motor and the pulse provides information indicative of the position of the motor.
15. The controller of claim 14 , wherein the square wave is a first high value at a first time and the pulse is a second high value at a second time, and wherein the first high value is different than the second high value.
16. The controller of claim 9 , wherein the second portion further includes a motor driver that receives the power signal over the wireless power transfer interface, and provides a power level to the motor based on the power signal, wherein the power signal is at least one of: an analog voltage or a pulse-width modulation (PWM) signal.
17. A method comprising:
receiving, by a controller on a first portion in a LIDAR system, from a second portion including a motor, and via a unidirectional data communication interface, upstream data indicative of a speed of the motor and a position of the motor that is encoded to remove data indicative of a direction of rotation of the motor,
wherein if the data indicative of the direction of rotation of the motor is variable, the controller is configured to generate the data indicative of the direction of rotation of the motor based on the data indicative of the position of the motor included in the upstream data and wherein the second portion rotates relative to the first portion; and
providing, via a wireless power transfer interface, to the second portion, and based on the encoded upstream data, a power signal used to provide power to the motor.
18. The method of claim 17 , further comprising:
adjusting, based on the encoded upstream data, the power signal, wherein the power signal is at least one of: an analog voltage or a pulse-width modulation (PWM) signal.
19. A method comprising:
receiving, by a controller on a first portion in a LIDAR system, from a second portion including a motor, and via a unidirectional data communication interface, upstream data indicative of a speed of the motor and a position of the motor that is encoded to remove data indicative of a direction of rotation of the motor,
wherein the encoded upstream data includes a first square wave and a first pulse, wherein the square wave provides information for the motor and the pulse provides information indicative of the position of the motor,
wherein the square wave is a first high value at a first time and the pulse is a second high value at a second time, and wherein the first high value is different than the second high value,
wherein the data indicative of the direction of rotation of the motor is removed from the encoded upstream data if known by previous upstream data,
wherein the second portion rotates relative to the first portion; and
providing, via a wireless power transfer interface, to the second portion, and based on the encoded upstream data, a power signal used to provide power to the motor.
20. The LIDAR system of claim 1 , wherein the motor is within the second portion and spaced from the first portion.