Multi-turn absolute encoder, encoding method and robot

1. A multi-turn absolute encoder, comprising a rotary shaft, wherein the multi-turn absolute encoder further comprises:

a control circuit board, one side of which is vertically provided with the rotary shaft;

a magnet, disposed on one side of the control circuit board, connected to the rotary shaft, and configured to synchronously rotate about the rotary shaft;

a Hall sensor, disposed at a position corresponding to the magnet on the other side of the control circuit board, and configured to acquire turn count information of the rotary shaft upon power interruption;

a controller, disposed on the control circuit board, electrically connected to the Hall sensor, power supplied by a battery, and configured to acquire data of the Hall sensor upon power interruption;

a primary controller, disposed on the control circuit board, and electrically connected to the controller;

a single-turn absolute encoder, disposed at a position below the magnet on one side of the control circuit board, electrically connected to the primary controller, and configured to acquire relative position information of the rotary shaft upon power on; and

a non-volatile memory, disposed on the control circuit board, electrically connected to the primary controller, and configured to, in power interruption, store absolute position information of the rotary shaft calculated by the primary controller prior to power interruption;

wherein the primary controller is configured to calculate the absolute position information of the rotary shaft based on the turn count information of the rotary shaft, the relative position information of the rotary shaft and the absolute position information of the rotary shaft stored in previous power interruption.

2. The multi-turn absolute encoder according to claim 1 , wherein the Hall sensor comprises a first bipolar Hall sensor and a second bipolar Hall sensor; wherein the first bipolar Hall sensor and the second bipolar Hall sensor are orthogonally disposed on the control circuit board, and wherein a distance between the Hall sensor and the magnet is less than or equal to 2.5 mm.

3. The multi-turn absolute encoder according to claim 1 , wherein the controller is a low power consumption controller.

4. The multi-turn absolute encoder according to claim 1 , wherein a distance between the single-turn absolute encoder and the magnet is less than or equal to 2 mm.

5. The multi-turn absolute encoder according to claim 1 , wherein the controller is connected to a power pin and a signal output pin of the Hall sensor respectively via a first pin and a second pin, and configured to open the first pin in power interruption, such that the first pin is in communication with the power pin.

6. The multi-turn absolute encoder according to claim 1 , wherein the primary controller is disposed on one side of the control circuit board, and wherein the controller is disposed on the other side of the control circuit board.

7. The multi-turn absolute encoder according to claim 1 , wherein the primary controller and the controller are connected via an I 2 C bus, and wherein the primary controller and the single-turn absolute encoder are connected via an SPI bus.

8. An encoding method of the multi-turn absolute encoder as defined in claim 1 , comprising:

in power interruption, storing, by the non-volatile memory, the absolute position information of the rotary shaft calculated by the primary controller prior to power interruption;

upon power interruption, in a first mode, controlling, by the controller, the Hall sensor to start operating, and acquiring the turn count information of the rotary shaft via the Hall sensor;

upon power on, in a second mode, controlling, by the controller, the Hall sensor not to operate, and acquiring, by the primary controller, the relative position information of the rotary shaft via the single-turn absolute encoder;

reading, by the primary controller, the absolute position information of the rotary shaft stored by the non-volatile memory in previous power interruption, the turn count information of the rotary shaft acquired by the controller upon power interruption, and the relative position information of the rotary shaft acquired by the single-turn absolute encoder upon power on; and

calculating, by the primary controller the absolute position information of the rotary shaft based on the absolute position information of the rotary shaft stored in the previous power interruption, the turn count information of the rotary shaft and the relative position information of the rotary shaft.

9. The method according to claim 8 , wherein in the first mode, the controller enables a timer and starts timing, the timer is interrupted when a timing period is reached, the Hall sensor is controlled to start operating, a level of the Hall sensor is detected, and a current turn count information of the rotary shaft is calculated.

10. The method according to claim 9 , wherein the controller is connected to a power pin and a signal output pin of the Hall sensor respectively via a first pin and a second pin, and wherein the controlling the Hall sensor to start operating comprises:

opening the first pin, such that the first pin is in communication with the power pin and power is supplied for the Hall sensor.

11. The method according to claim 8 , wherein in the second mode, the controller disables the timer.

12. The method according to claim 8 , wherein the controller judges power interruption and power on based on an external interrupt signal.

13. The method according to claim 8 , wherein the reading, by the primary controller, the turn count information of the rotary shaft acquired by the controller upon power interruption comprises:

sending, by the primary controller, an address of the controller to the controller;

receiving, by the controller, the address, and judging whether the address matches a practical address of the controller;

returning, by the controller, an address match acknowledge message to the primary controller if the controller judges that the address matches the practical address of the controller;

sending, by the primary controller, a data read instruction to the controller; and

returning, by the controller, the acquired turn count information of the rotary shaft to the primary controller based on the received data read instruction.

14. The method according to claim 8 , wherein the calculating, by the primary controller the absolute position information of the rotary shaft based on the absolute position information of the rotary shaft stored in previous power interruption, the turn count information of the rotary shaft and the relative position information of the rotary shaft is performed based on:

W=INT (X+Y)+Z; wherein W represents the absolute position information of the rotary shaft, X represents the absolute position information of the rotary shaft stored in previous power interruption, Y represents the turn count information of the rotary shaft, Z represents the relative position information of the rotary shaft, and INT represents rounding up.

15. A robot, comprising a multi-turn absolute encoder, wherein the multi-turn absolute encoder comprises a rotary shaft, and wherein the multi-turn absolute encoder further comprises:

a control circuit board, one side of which is vertically provided with the rotary shaft;

a magnet, disposed on one side of the control circuit board, connected to the rotary shaft, and configured to synchronously rotate about the rotary shaft;

a Hall sensor, disposed at a position corresponding to the magnet on the other side of the control circuit board, and configured to acquire turn count information of the rotary shaft upon power interruption;

a controller, disposed on the control circuit board, electrically connected to the Hall sensor, power supplied by a battery, and configured to acquire data of the Hall sensor upon power interruption;

a primary controller, disposed on the control circuit board, and electrically connected to the controller;

a single-turn absolute encoder, disposed at a position below the magnet on one side of the control circuit board, electrically connected to the primary controller, and configured to acquire relative position information of the rotary shaft upon power on; and

a non-volatile memory, disposed on the control circuit board, electrically connected to the primary controller, and configured to, in power interruption, store absolute position information of the rotary shaft calculated by the primary controller prior to power interruption;

wherein the primary controller is configured to calculate the absolute position information of the rotary shaft based on the turn count information of the rotary shaft, the relative position information of the rotary shaft and the absolute position information of the rotary shaft stored in previous power interruption.

16. The robot according to claim 15 , wherein the Hall sensor comprises a first bipolar Hall sensor and a second bipolar Hall sensor; wherein the first bipolar Hall sensor and the second bipolar Hall sensor are orthogonally disposed on the control circuit board, and wherein a distance between the Hall sensor and the magnet is less than or equal to 2.5 mm.

17. The robot according to claim 15 , wherein the controller is a low power consumption controller.

18. The robot according to claim 15 , wherein a distance between the single-turn absolute encoder and the magnet is less than or equal to 2 mm.

19. The robot according to claim 15 , wherein the controller is connected to a power pin and a signal output pin of the Hall sensor respectively via a first pin and a second pin, and configured to open the first pin in power interruption, such that the first pin is in communication with the power pin.

20. The robot according to claim 15 , wherein the primary controller is disposed on one side of the control circuit board, and wherein the controller is disposed on the other side of the control circuit board.