A method for correcting encoder data

Abstract

A method for correcting encoder data is characterized by employing two independent detection circuits on a mechanical gear encoder. The two circuits exchange data via a serial interface. Each circuit sends its own encoder position data and timestamp to the other circuit. Each circuit determines the correctness of the data according to the following method: reading the master gear position data and the first slave gear position data from a first detection circuit. If the deviation between the two sets of data exceeds a threshold, the detection circuit data is judged to be erroneous; otherwise, it is used as the position data output by the first detection circuit. If the difference in the position data output by the two detection circuits is within a threshold, the encoder data is judged to be correct. Compared with the prior art, the advantages of this method are that the use of two independent detection circuits allows each piece of data to be compared and verified, preventing the transmission of erroneous data. The use of independent external interfaces improves interface security.

Description

Technical Field

[0001] The present invention relates to the field of absolute value encoders, and in particular to an encoder data correction method. Background Art

[0002] Currently, encoders are categorized by function as single-turn and multi-turn encoders. Single-turn encoders can only encode the absolute value of the rotation angle, while multi-turn encoders retain the angle measurement function of single-turn encoders while also measuring the number of rotations. Single-turn encoders can be categorized by their detection principle as photoelectric, magnetic, and inductive. Multi-turn encoders are implemented in three forms: battery-operated multi-turn, Wiegand multi-turn, and gear multi-turn. Encoders based on these principles have significantly different circuit topologies, but all utilize a processor to convert data into absolute values ​​and transmit detection data via a fieldbus. This circuit structure can cause the encoder to lose all functionality and fail if errors occur in the detection circuit or detection data. Summary of the Invention

[0003] The present invention addresses the issues with the aforementioned encoder solution by employing innovative circuit design and algorithms, employing two redundant, completely independent circuits. The detection information acquired by each circuit is transmitted to the other processor via bus communication via its own processor. Each processor detects its own data, the other processor's data, and past data, determines whether its own detected data is functioning properly, and corrects any erroneous data. Data exchange occurs through the two processors.

[0004] A gear-type magnetic multi-turn encoder is used to simultaneously detect the absolute angle of each gear through two independent detection circuits. The principle of gear ratio is used to form two independent sets of single and multi-turn data. Through the interaction between processors, the self, each other and past data are detected to form reliable position data and avoid the situation where any circuit error or data error causes the encoder to fail completely.

[0005] The present invention provides an encoder data correction method, which is characterized by: using two independent detection circuits on a mechanical gear encoder, the two circuits exchange data via a serial interface, each circuit sends its own encoder position data and timestamp to the other circuit, and each circuit determines the correctness of the data according to the following method;

[0006] Read the master gear position data and the first slave gear position data of the first detection circuit. If the deviation between the two sets of data is greater than a threshold, it is determined that the detection circuit data is wrong. Otherwise, it is used as the position data output by the first detection circuit;

[0007] If the difference between the position data output by the two sets of detection circuits is within the threshold range, it is determined that the encoder data is correct;

[0008] Store the correct encoder data value and timestamp;

[0009] Calculate and store the instantaneous speed obtained by correct data;

[0010] Adjust the position threshold range and speed threshold range according to the instantaneous speed;

[0011] When the difference between the two sets of data is greater than the threshold range, the instantaneous speed of each position data and the most recent correct position data is calculated;

[0012] Calculate the difference between the two sets of instantaneous speeds and the most recent correct instantaneous speed, and determine that the data with a small difference and within the speed threshold range is correct;

[0013] Each group of circuits independently uses an external interface to send correct data through the above interface.

[0014] The mechanical gear encoder includes: a main body, which is provided with a main shaft hole and two bearing chambers for accommodating bearings; a gear frame, which is provided with several holes for fixing the gear shaft; a main shaft, which passes through the main shaft hole and is fixed to the main body by bearings to form a main shaft system; a main gear, which is sleeved on one end of the main shaft and is provided with a first magnet mounting position; a main gear magnet, which is fixed to the first magnet mounting position; several gear shafts, which are mounted on the gear frame; several gears, which are correspondingly sleeved on the gear shafts; the gear shafts have magnet mounting positions, and each gear is meshed with each other in sequence; a slave gear magnet, which is mounted on the magnet mounting position of the slave gear, and a magnetic absolute value sensor is installed directly above the center of rotation of the magnet.

[0015] The magnetic absolute value sensor has two independent detection circuits, which belong to the detection circuit respectively; the detection circuit is composed of a main magnetic absolute value sensor and three slave magnetic absolute value sensors.

[0016] The two detection circuits are respectively connected to the two processing devices, and the communication interface between the detection circuit and the processing device is an SPI interface; the two detection circuits are respectively connected to the two processing devices, and the communication interface between the detection circuit and the processing device is an SPI interface; the circuit board used includes: a voltage conversion unit, used to convert the power supply voltage of an external power supply into the working voltage required by the internal chip of the circuit board; a main gear detection unit, used to detect the rotation angle of the main gear, three slave gear detection units, used to detect the angles of the three slave gears, two processing device units, and two external interface units.

[0017] There is a communication interface between one group of processing devices, which is a serial interface. There are signal lines between the processing devices, which are two unidirectional signal lines.

[0018] The processing devices have their own independent external interfaces.

[0019] The two groups of detection circuits, processing devices and external interfaces are each powered by a group of independent voltage conversion units.

[0020] Two of the processing units have internal storage devices.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] The encoder data correction method described in this invention utilizes two independent detection circuits, allowing each piece of data to be compared and verified. This prevents the transmission of erroneous data and utilizes independent external interfaces, improving interface security. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0024] Figure 1 Flowchart of the encoder data correction method. DETAILED DESCRIPTION

[0025] The present invention will be further explained below with reference to specific embodiments.

[0026] The present invention provides an encoder data correction method, which is characterized by: using two independent detection circuits on a mechanical gear encoder, the two circuits exchange data via a serial interface, each circuit sends its own encoder position data and timestamp to the other circuit, and each circuit determines the correctness of the data according to the following method;

[0027] The master gear position data and the first slave gear position data of the first detection circuit are read. If the deviation between the two sets of data is greater than a threshold, it is determined that the detection circuit data is wrong. Otherwise, it is used as the position data output by the first detection circuit.

[0028] If the difference in position data output by the two sets of detection circuits is within the threshold range, it is determined that the encoder data is correct.

[0029] Stores the correct encoder data value and timestamp.

[0030] Calculate and store the instantaneous speed obtained from the correct data.

[0031] Adjust the position threshold range and speed threshold range according to the instantaneous speed.

[0032] When the difference between the two sets of data is greater than the threshold range, the instantaneous speed of each position data and the most recent correct position data is calculated.

[0033] Calculate the difference between the two sets of instantaneous speeds and the most recent correct instantaneous speed, and determine that the data with a small difference and within the speed threshold range is correct;

[0034] Each group of circuits independently uses an external interface to send correct data through the above interface.

[0035] The mechanical gear encoder includes: a main body, which is provided with a main shaft hole and two bearing chambers for accommodating bearings; a gear frame, which is provided with several holes for fixing the gear shaft; a main shaft, which passes through the main shaft hole and is fixed to the main body by bearings to form a main shaft system; a main gear, which is sleeved on one end of the main shaft and is provided with a first magnet mounting position; a main gear magnet, which is fixed to the first magnet mounting position; several gear shafts, which are mounted on the gear frame; several gears, which are correspondingly sleeved on the gear shafts; the gear shafts have magnet mounting positions, and each gear is meshed with each other in sequence; a slave gear magnet, which is mounted on the magnet mounting position of the slave gear, and a magnetic absolute value sensor is installed directly above the center of rotation of the magnet.

[0036] The magnetic absolute value sensor has two independent detection circuits, which belong to the detection circuit respectively; the detection circuit is composed of a main magnetic absolute value sensor and three slave magnetic absolute value sensors.

[0037] The two detection circuits are respectively connected to the two processing devices, and the communication interface between the detection circuit and the processing device is an SPI interface; the two detection circuits are respectively connected to the two processing devices, and the communication interface between the detection circuit and the processing device is an SPI interface; the circuit board used includes: a voltage conversion unit, used to convert the power supply voltage of an external power supply into the working voltage required by the internal chip of the circuit board; a main gear detection unit, used to detect the rotation angle of the main gear, three slave gear detection units, used to detect the angles of the three slave gears, two processing device units, and two external interface units.

[0038] There is a communication interface between one group of processing devices, which is a serial interface. There are signal lines between the processing devices, which are two unidirectional signal lines.

[0039] The processing devices have their own independent external interfaces.

[0040] The two groups of detection circuits, processing devices and external interfaces are each powered by a group of independent voltage conversion units.

[0041] Two of the processing units have internal storage devices.

[0042] Matters not covered by the present invention are known technologies.

[0043] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for correcting encoder data, characterized in that: The mechanical gear encoder uses two independent detection circuits that exchange data via a serial interface. Each circuit sends its own encoder position data and timestamp to the other circuit. Each circuit determines the correctness of the data using the following method: Read the master gear position data and the first slave gear position data of the first detection circuit. If the deviation between the two sets of data is greater than a threshold, it is determined that the detection circuit data is wrong. Otherwise, it is used as the position data output by the first detection circuit; If the difference between the position data output by the two sets of detection circuits is within the threshold range, it is determined that the encoder data is correct; Store the correct encoder data value and timestamp; Calculate and store the instantaneous speed obtained by correct data; Adjust the position threshold range and speed threshold range according to the instantaneous speed; When the difference between the two sets of data is greater than the threshold range, the instantaneous speed of each position data and the most recent correct position data is calculated; Calculate the difference between the two sets of instantaneous speeds and the most recent correct instantaneous speed, and determine that the data with a small difference and within the speed threshold range is correct; Each group of circuits independently uses an external interface to send correct data via a serial interface; The mechanical gear encoder comprises: a main body, which is provided with a main shaft hole and two bearing chambers for accommodating bearings; a gear frame, which is provided with a plurality of holes for fixing the gear shaft; a main shaft, which passes through the main shaft hole and is fixed to the main body through bearings to form a main shaft system; a main gear, which is sleeved on one end of the main shaft and is provided with a first magnet mounting position; a main gear magnet, which is fixed to the first magnet mounting position; a plurality of gear shafts, which are mounted on the gear frame; a plurality of gears, which are correspondingly sleeved on the gear shafts; the gear shafts have magnet mounting positions, and each gear is meshed with each other in sequence; a slave gear magnet, which is mounted on the magnet mounting position of the slave gear, and a magnetic absolute value sensor is mounted just above the center of rotation of the magnet; The magnetic absolute value sensor has two independent detection circuits, which belong to the detection circuit respectively; the detection circuit is composed of a main magnetic absolute value sensor and three slave magnetic absolute value sensors; The two detection circuits are respectively connected to the two processing devices, and the communication interface between the detection circuit and the processing device is an SPI interface; the circuit board used includes: a voltage conversion unit, used to convert the supply voltage of an external power supply into the operating voltage required by the internal chip of the circuit board; a main gear detection unit, used to detect the rotation angle of the main gear, three slave gear detection units, used to detect the angles of the three slave gears, two processing device units, and two external interface units.

2. The encoder data correction method according to claim 1, wherein: There is a communication interface between the two processing devices, and the communication interface is a serial interface; there are signal lines between the processing devices, and the signal lines are two unidirectional signal lines.

3. The encoder data correction method according to claim 1, wherein: The processing devices have their own independent external interfaces.

4. The encoder data correction method according to claim 1, wherein: The two groups of detection circuits, processing devices and external interfaces are each powered by a group of independent voltage conversion units.

5. The encoder data correction method according to claim 1, wherein: Two of the processing units have internal storage devices.

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