Disclosure of Invention
The invention aims to provide a double-Hall angle and length measuring module, a double-Hall angle and length measuring device and a double-Hall angle and length measuring method, and aims to solve the technical problems of complex structure, large occupied space and low measuring precision of a length measuring device in the prior art.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows: a double-Hall angle and length measuring module comprises a mounting bracket and a circuit board which are arranged in parallel, wherein the circuit board is fixedly connected with the mounting bracket through a plurality of supporting columns; the angle measuring gear shaft and the ring counting gear shaft are respectively installed on the installation support through a first bearing assembly, an angle measuring magnet is arranged at one end of the angle measuring gear shaft facing the circuit board, and an angle measuring gear is arranged at the other end of the angle measuring gear shaft; a ring counting magnet is arranged at one end of the ring counting gear shaft facing the circuit board, and a ring counting gear is arranged at the other end of the ring counting gear shaft; an angle measuring Hall chip opposite to the angle measuring magnet and a circle measuring Hall chip opposite to the circle measuring magnet are arranged on one side, facing the mounting bracket, of the circuit board; the angle measuring gear and the ring counting gear are meshed with each other, no common divisor exists between the number of teeth of the angle measuring gear and the number of teeth of the ring counting gear, and the number of the teeth of the ring counting gear is prime.
Furthermore, each first bearing assembly comprises a bearing seat, the bearing seat is fixedly connected with the mounting bracket, and two sets of bearings are arranged in the bearing seats.
A double-Hall angle and length measuring device comprises a shell, a winding drum, a transmission shaft and the double-Hall angle and length measuring module, wherein the transmission shaft is installed on the shell through a second bearing assembly, one end of the transmission shaft is fixedly connected with the winding drum, the other end of the transmission shaft is fixedly connected with a transmission gear, and the transmission gear is meshed with an angle measuring gear; and an energy storage mechanism is arranged on the transmission shaft.
Furthermore, the energy storage mechanism comprises a plurality of rings of spring steel sheets surrounding the transmission shaft, one end of each spring steel sheet is fixed on the transmission shaft, and the other end of each spring steel sheet is fixedly connected with the shell.
Further, the second bearing assembly includes a first bearing and a second bearing, and the stored energy mechanism is located between the first bearing and the second bearing.
Furthermore, a detachable upper cover is arranged on the shell, and a sealing ring is arranged between the upper cover and the shell.
A double-Hall angle and length measuring method adopts the double-Hall angle and length measuring device, and comprises the following steps: collecting the rotation angle of the angle measurement gear through the angle measurement Hall chip; acquiring the rotation angle of the ring counting gear through a ring counting Hall chip; judging the number of turns of the angle measuring gear according to the rotation angle of the angle measuring gear and the rotation angle of the ring counting gear; and determining the total angle of the angle measuring gear through the number of turns of the angle measuring gear and the current angle, and further determining the extending length of the length measuring line on the winding drum.
Further, according to the rotation angle of the angle measuring gear and the rotation angle of the ring counting gear, the number of turns of the angle measuring gear is judged, and the method specifically comprises the following steps: when the number of turns of rotation of the angle measuring gear is less than or equal to the number of teeth of the ring counting gear, the angle measuring gear is taken as a reference, namely when the angle measuring gear rotates to the same position every time, the positions of the ring counting gear are different, and the angle difference value between every two adjacent positions is 360/Zc, wherein Zb is the number of teeth of the angle measuring gear, Zc is the number of teeth of the ring counting gear, and the absolute angle difference value at each position is 360/Zc at the minimum; when the number of rotation turns of the angle measuring gear is larger than the number of teeth of the ring counting gear, the ring counting gear starts a new period again; by reading the reading b of the angle measurement Hall chip and the reading c of the circle counting Hall chip, substituting the following formula:
wherein: nb is the number of turns of the angle measuring gear, is a natural number between 0 and Zc, and b is the current angle of the angle measuring gear; nc is the number of turns of the ring counting gear, a natural number from 0 to Zb, and c is the current angle of the ring counting gear; ib is the transmission ratio of the angle measuring gear and the ring counting gear, namely the value of Zb/Zc; when Nc takes 0-Zb, and Nb has only one integer from 0-Zc, the integer Nb obtained by calculation at this time is the number of turns of the angle measuring gear.
Compared with the prior art, the invention has the following beneficial effects:
(1) the invention only needs two gears for transmission, and the measured number of turns is irrelevant to the transmission ratio and only relevant to the number of teeth, and the number Zc of the teeth of the ring counting gear is only needed to be properly increased without a mode of greatly increasing the transmission ratio on occasions with more requirements on the number of measured turns, so that the invention has the characteristics of simple and reliable structure, high measurement precision, low cost and the like;
(2) the length measuring module and the length measuring device have uniqueness of total rotation angle in a measuring range, namely length uniqueness, and when the device is powered off and then powered on again, the length of the extended or pulled-back length of the length measuring line on the winding drum can be directly judged according to the current angles of the angle measuring gear and the ring counting gear.
Detailed Description
The invention is further described below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
The first embodiment is as follows:
as shown in fig. 1 to 4, a dual hall length measuring module includes a mounting bracket 1 and a circuit board 2 which are arranged in parallel, wherein the circuit board 2 is fixedly connected with the mounting bracket 1 through 2 positioning holes and 4 supporting columns 3; the angle measuring gear shaft 5 and the ring counting gear shaft 6 are respectively installed on the installation support 1 through first bearing assemblies, an angle measuring magnet 51 is fixed at one end of the angle measuring gear shaft 5 facing the circuit board 2 in a bonding or interference fit mode, and the other end of the angle measuring gear shaft is fixedly connected with an angle measuring gear 52 in an in-mold injection molding or threaded connection or interference fit mode; a ring counting magnet 61 is fixed at one end of the ring counting gear shaft 6 facing the circuit board 2 in a bonding or interference fit mode, and the other end of the ring counting gear shaft is fixedly connected with a ring counting gear 62 in an in-mold injection molding or threaded connection or interference fit mode; an angle measuring Hall chip 21 opposite to the angle measuring magnet 51 and a circle measuring Hall chip 22 opposite to the circle measuring magnet 61 are arranged on one side of the circuit board 2 facing the mounting bracket 1; the angle measuring gear 52 is meshed with the ring counting gear 62, no common divisor exists between the tooth number Zb of the angle measuring gear 52 and the tooth number Zc of the ring counting gear, and the tooth number Zc of the ring counting gear is prime; when the number of rotation turns of the angle measuring gear 52 is less than or equal to the number of teeth of the ring counting gear 62, and the angle measuring gear 52 is taken as a reference, that is, when the angle measuring gear 52 rotates to the same position every time, the positions of the ring counting gear 62 are different, and the angle difference between two adjacent positions is 360/Zc.
In this embodiment, each first bearing assembly includes a bearing seat 41, the bearing seat 41 is fixedly connected with the mounting bracket 1, and two rolling bearings are arranged in the bearing seat 41; the angle measuring gear shaft 5 and the ring counting gear shaft 6 are both supported by double bearings to carry out stable transmission, so that unstable transmission caused by radial force in the gear transmission process is reduced, the transmission error is reduced, and the transmission precision is improved; meanwhile, the friction loss of the gear can be reduced, and the service life is prolonged. The mounting bracket 1 is in a structure like a Chinese character 'ji', the angle measuring gear 52 and the ring counting gear 62 are arranged at the sunken part of the mounting bracket 1, so that the structure is more compact, and one side of the mounting bracket 1 is provided with an L-shaped second bracket 11 for fixing a slip ring connected with the circuit board 2; the second bracket 11 is integrally formed with the mounting bracket 1. The angle measuring gear shaft 5 and the angle measuring gear 52 can also adopt an integrally formed structure, and the integrally formed design can reduce the transmission error caused by the installation clearance and improve the transmission precision; similarly, the ring gear shaft 6 and the ring gear 62 may be integrally formed. This embodiment only needs two gear drive, and the number of turns that can measure is irrelevant with drive ratio, only relevant with the number of teeth, need not to need more occasion to the number of turns of measuring through the mode that increases drive ratio by a wide margin, only need increase the number of teeth Zc of meter ring gear can, have simple structure, reliable, measurement accuracy is high, characteristics such as material cost low.
Example two:
the difference between this embodiment and the first embodiment is that in this embodiment, there is no common divisor between the number of teeth Zb of the angle measuring gear 52 and the number of teeth Zc of the ring counting gear 62, and the number of teeth of the ring counting gear 62 is prime.
Example three:
based on the double-hall length measuring module described in the first embodiment and the second embodiment, the present embodiment provides a double-hall length measuring device, which includes a housing 7, a winding drum 8, and a transmission shaft 9, wherein the transmission shaft 9 is mounted on the housing 7 through a second bearing assembly, one end of the transmission shaft 9 is fixedly connected with the winding drum 8, the other end is fixedly connected with a transmission gear 91, and the transmission gear 91 is meshed with the angle measuring gear 52; the energy storage mechanism is arranged on the transmission shaft 9 and comprises a plurality of rings of spring steel sheets 92 surrounding the transmission shaft 9, one end of each spring steel sheet 92 is fixed on the transmission shaft 9, and the other end of each spring steel sheet 92 is fixedly connected with the shell 7. The double-hall length measuring module according to the first embodiment or the second embodiment is fixedly connected with the housing 7 through the mounting bracket 1.
A steel wire rope or a cable and other length measuring lines are wound on the winding drum 8, when the length measuring lines on the winding drum 8 are pulled out, the winding drum 8 rotates and drives the angle measuring gear 52 through the transmission shaft 9 and the transmission gear 91, the angle measuring gear 52 drives the ring counting gear 62 to rotate, the angle measuring gear 52 and the ring counting gear 62 respectively drive the angle measuring magnet 51 and the ring counting magnet 61 through the angle measuring gear shaft 5 and the ring counting gear shaft 6, and the angle measuring Hall chip 21 senses the change of the magnetic field of the angle measuring magnet 51 and then outputs the angle position of the angle measuring gear 52 through the circuit board 2; the angle position of the ring counting gear 62 is output through the circuit board 2 after the ring counting Hall chip 22 induces the magnetic field change of the ring counting magnet 61; the CPU mounted on the circuit board 2 calculates the length of the drawn length of the length measuring wire based on preset parameters (including the number of teeth Zb of the angle measuring gear 52, the number of teeth Zc of the ring counting gear 62, the number of teeth of the transmission gear 91, structural parameters of the spool 8, etc.).
When the length measuring line on the winding drum 8 is pulled out, the spring steel sheet 92 is gradually deformed and tightened and wound on the transmission shaft 9 under the driving of the transmission shaft 9, when the external force stretching the length measuring line is removed or reduced to a certain value, the potential energy generated by the deformation of the spring steel sheet 92 can be released, so that the transmission shaft 9 is driven to rotate reversely to wind the length measuring line on the winding drum 8 again, and the reset effect is achieved. The second bearing assembly comprises a first bearing 71 and a second bearing 72, and the stored energy mechanism is located between the first bearing 71 and the second bearing 72; on one hand, the transmission shaft 9 can be prevented from being inclined in the process of driving the transmission shaft 9 by the energy storage mechanism, and the rotation stability of the transmission shaft 9 is improved; on the other hand, when the length measuring line on the winding drum 8 is pulled out, radial unbalanced force is generated on the transmission shaft 9, so that transmission error is generated, and the transmission error caused by bearing play is reduced through the double-bearing structure provided with the first bearing 71 and the second bearing 72, so that the transmission precision is improved, and further the length measuring precision is improved.
Be equipped with removable upper cover 73 on casing 7, be equipped with sealing washer 74 between upper cover 73 and the casing 7, removable upper cover 73 can improve the convenience of overhauing, and sealing washer 74 can improve the leakproofness between upper cover 73 and the casing 7 simultaneously, effectively protects each part in the casing 7, improves the reliability and the life of device.
Example four:
based on the second to third embodiments, the present embodiment provides a dual hall length measurement method, including:
the rotation angle of the angle measuring gear 52 is collected through the angle measuring Hall chip 21;
the rotation angle of the ring counting gear 62 is acquired through the ring counting Hall chip 22;
according to the rotation angle of the angle measuring gear 52 and the rotation angle of the ring counting gear 62, the number of turns of the angle measuring gear 52 is judged, specifically:
because there is no common divisor or is a prime number between the tooth number Zb of the angle measuring gear 52 and the tooth number Zc of the ring counting gear 62, when the number of turns of the angle measuring gear 52 is less than or equal to the tooth number of the ring counting gear 62, the angle measuring gear 52 is taken as a reference, that is, when the angle measuring gear 52 rotates to the same position each time, the positions of the ring counting gear 62 can be ensured to be different, the angle difference value between two adjacent positions is 360/Zc, and the absolute angle difference value at each position is 360/Zc at the minimum; because Zc is prime number, the number in the phase difference 360/Zc x (0-Zc) is not repeated, so that the unique value of Nb in the measuring range (0-Zc circle) can be solved by using the phase difference, and when the number of the rotating circles Nb of the angle measuring gear 52 is greater than the number of teeth Zc of the ring counting gear 62, the ring counting gear 62 starts a new period again; reading an angle b through the angle measuring Hall chip 21 and reading an angle c through the circle counting Hall chip 22, and substituting the following formulas:
wherein:
nb is the number of turns of the angle measuring gear, is a natural number between 0 and Zc, and b is the current angle of the angle measuring gear;
nc is the number of turns of the ring counting gear, a natural number from 0 to Zb, and c is the current angle of the ring counting gear;
ib is the transmission ratio of the angle measuring gear and the ring counting gear, namely the value of Zb/Zc;
when Nc takes 0-Zb numbers to be circularly substituted into the formula (1), and Nb has only an integer from 0-Zc, the integer Nb obtained by calculation at the moment is the number of turns of the angle measuring gear.
The specific dual hall algorithm is as follows:
parameter definition:
a: total angle of rotation of the drive shaft
Acal: calculated total angle of rotation of the drive shaft
Na: number of turns of the driving shaft
a: single rotation angle of driving shaft
And Za: number of teeth of driving shaft gear
Nb: number of turns of angle measuring gear
b: single-turn angle of angle-measuring gear, i.e. reading of angle-measuring Hall chip
Zb: measuring the number of teeth of a gear
Nc: number of turns of ring counting gear
c: single-turn angle of ring-counting gear, i.e. reading of ring-counting Hall chip
And Zc: counting the number of teeth of a ring gear
ia: drive ratio of drive shaft gear to angle measuring gear
ib: transmission ratio of angle measuring gear and ring counting gear
According to the gear transmission relationship:
ia=Za/Zb,ib=Zb/Zc
a=mod(A,360)
b=mod(A·ia,360)
c=mod(A·ia·ib,360)
the concept of introducing a loop:
b=mod((Na·360+a)·ia,360)
c=mod((Na·360+a)·ia·ib,360)
=mod((Nb·360+b)·ib,360)
general derivation of Nb solution:
(Nb·360+b)·ib=Nc·360+c
Nb·360·ib=Nc·360+c-b·ib
bn (n is a natural number from 0 to Zb) is the starting angle of the angle measuring gear b corresponding to each circle when the ring counting gear c is equal to 0;
cn (n is a natural number from 0 to Zc) is a start angle of the goniometer gear c corresponding to each revolution when the ring counter gear b is 0.
Then: b is bn + Δ b
c=cn+Δc
B0 and c0 are substituted into the formula (2) to obtain:
from the gear ratio relationship: Δ c- Δ b · ib ═ 0
Then turn 0:
the nth turn:
because bn and cn are phase differences between b and c and are not repeated in the cycle of Zc, Nc is a natural number from 0 to Zc;
therefore: within the Zc circle, Nb has a unique solution.
Because Nb belongs to natural numbers from 0 to Zc, Nc belongs to natural numbers from 0 to Zb; b. c is data read from the hall chip, so the Nc is substituted into the formula (2) one by one from a natural number of 0 to Zb, if Nb also satisfies the natural number of 0 to Zc, then Nb at this time is the number of rotations of the goniometric gear that we need to obtain, namely:
Acal=(Nb·360+b)/ib (4)
the total angle of the rotation of the angle measuring gear 52 is determined through the number of the rotation of the angle measuring gear 52 and the current angle, and the extending length of the length measuring line on the winding drum 8 can be further determined. By adopting the method, even if power failure occurs, the length measuring line on the winding drum 8 is pulled out or retracted after the power failure, and the length of the pulled out or retracted length measuring line on the winding drum 8 can be directly judged according to the current angles of the angle measuring gear 52 and the ring counting gear 62 after power failure, so that the angle measuring module, the length measuring module and the angle measuring device have power failure memory functions.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.