US 2014/0278223 A1 · DEVICE AND METHOD FOR DETECTING ABSOLUTE MULTI-TURN ROTATION ANGLE

Abstract

The invention provides a device and method for detecting an absolute multi-turn rotation angle. The device comprises a housing, a cover plate and a rotating shaft, the rotating shaft being placed go through the housing. The rotating shaft is fixed with a main gear, the main gear is meshed with driven gears having a teeth number smaller than that of the main gear, the driven gears comprise a large driven gear and a small driven gear, the main gear is externally meshed with the large driven gear, the driven gears are connected with a two-stage speed reduction device which enables the rotating shaft to rotate multiple circles to slow down to a circle-number gear and enables the circle-number gear to rotate one circle only, both the driven gears and the circle-number gear are provided with bearings, the bearings have magnets therein, and the two magnets are relatively fixed with the driven gears and the circle-number gear, respectively, the top edges of the bearings fit with a PCB board, angle sensing chips which are fixed on the PCB board are above the magnets, the angle sensing chips are apart from the upper surfaces of the magnets by a fixed distance, the cover plate is fixed on the housing, and the housing and the cover plate fix the position of the PCB board by means of fitting. By the device and the method, the solution of the detected rotation angels is high; in addition, the algorithm is simple, and the fault-proofing capability is high.

Claims11

Dependent claims

A device for detecting an absolute multi-turn rotation angle, comprising a housing, a cover plate and a rotating shaft, the rotating shaft being placed within the housing, characterized in that the rotating shaft is fixed with a main gear, the main gear is meshed with driven gears having a teeth number smaller than that of the main gear, the driven gears comprise a large driven gear and a small driven gear, the main gear is externally meshed with the large driven gear, the driven gears are connected with a two-stage speed reduction device which enables the rotating shaft to rotate multiple circles to slow down to a circle-number gear and enables the circle-number gear to rotate one circle only, both the driven gears and the circle-number gear are provided with bearings, the bearings have magnets therein, and the two magnets are relatively fixed with the driven gears and the circle-number gear, respectively, the top edges of the bearings fit with a PCB board, angle sensing chips which are fixed on the PCB board are above the magnets, the angle sensing chips are apart from the upper surfaces of the magnets by a fixed distance, the cover plate is fixed on the housing, and the housing and the cover plate fix the position of the PCB board by means of fitting.

A method for detecting an absolute multi-turn rotation angle, comprising the following steps:

(1) determining constant values in the detection device, wherein the teeth number of the main gear is Z1, the teeth number of the small driven gear is Z21, the teeth number of the large driven gear is Z22, the teeth number of the middle small gear is Z31, the teeth number of the middle large gear is Z32, and the teeth number of the circle-number gear is Z34;
(2) based on the above constant values, determining that the transmission ratio between the main gear and the driven gears is m=Z1/Z22, the transmission ratio between the driven gears and the middle gear is n=Z32/Z21*Z34/Z31, and the full range is A=(n/m)*2π;
(3) performing calibration to designate the zero position, reading, storing and recording an angle Angle_Alpha0 and Circle_phi0 output by the angle sensing chips during calibration;
(4) detecting the rotation angles of the driven gears and the circle-number gear rotate respectively by the angle sensing chips disposed on the driven gears and the circle-number gear, compensation is performed after original angle signals output by the corresponding chips are read, that is, the Angle_Alpha0 and Circle_phi0 which are stored and recorded during calibration are subtracted from the read original angle signals;
rotation angle signals of Angle_Alpha and Circle_phi are output after compensation, respectively;
(5) calculating the rotation circle number i of the driven gears 32 according to formula i=floor(Circle_phi/Circlestep), where, CircleStep=2π/n, and imax=A/2π*(n−1);
(6) calculating the rotation angle of the main gear according to formula θ=Angle_Alpha/m+i*2π/m based on the rotation angle signal Angle_Alpha output by the angle sensing chips and the rotation circle number i of the driven gears;
and,
(7) converting the angles from θ to range A are converted to an angle θ from −A/2 to +A/2 and then outputting.

6 more elements

Dependencies are inferred from the claim text.

Device and method for detecting absolute multi-turn rotation angle

Life of this patent

Device and method for detecting absolute multi-turn rotation angle

Life of this patent

Abstract

Claims11