Mechanical multi-turn absolute time grating encoder
1. The utility model provides a gate encoder when absolute formula of machinery multiturn which characterized in that: the device comprises a first rotating shaft (1), a second rotating shaft (2), a third rotating shaft (3), a first time grating angle sensing unit (4), a second time grating angle sensing unit (5) and a signal processing system;
the first rotating shaft (1) is provided with a magnetic conductive first eccentric shaft neck (12), and the first rotating shaft (1) is coaxially fixed with a gear number z1The magnetic conductive first gear (11) and the second rotating shaft (2) are coaxially fixed with a gear number z2And a second gear (21) having a number of teeth z3The third rotating shaft (3) is provided with a magnetic conduction second eccentric shaft neck (32), and the third rotating shaft (3) is coaxially fixed with a gear number z4The first gear (11) is meshed with the second gear (21), and the third gear (22) is meshed with the fourth gear (31); wherein, let M be z1*z3,N=z2*z4M and N are prime numbers;
the first time grating angle sensing unit (4) comprises a first fan-shaped fixed measuring head (41) and a first circular fixed measuring head (42), the first fan-shaped fixed measuring head (41) is coaxially arranged on the outer side of the first gear (11) in a side-by-side mode, a gap is reserved between the first fan-shaped fixed measuring head and the first gear (11), the first circular fixed measuring head (42) is sleeved outside the first eccentric shaft neck (12) and a gap is reserved between the first circular fixed measuring head and the first eccentric shaft neck (12), and the axis of the first circular fixed measuring head (42) is overlapped with the axis of the first rotating shaft (1); the second time grating angle sensing unit (5) comprises a second fan-shaped annular fixed measuring head (51) and a second annular fixed measuring head (52), the second fan-shaped annular fixed measuring head (51) is coaxially arranged on the outer side of the fourth gear (31), a gap is reserved between the second fan-shaped annular fixed measuring head and the fourth gear (31), the second annular fixed measuring head (52) is sleeved outside the second eccentric shaft neck (32), a gap is reserved between the second annular fixed measuring head and the second eccentric shaft neck (32), and the axis of the second annular fixed measuring head (52) is superposed with the axis of the second rotating shaft (2); the first fan-shaped annular measuring head (41), the first annular measuring head (42), the second fan-shaped annular measuring head (51) and the second annular measuring head (52) are connected with a signal processing system;
the signal processing system generates an excitation signal to act on an excitation coil on a first fan-shaped fixed measuring head (41), a first annular fixed measuring head (42), a second fan-shaped fixed measuring head (51) and a second annular fixed measuring head (52), when a first rotating shaft (1) rotates as a driving shaft, a second rotating shaft (2) and a third rotating shaft (3) rotate as a driven shaft, the signal processing system processes the induction signal output by the induction coil on the first fan-shaped fixed measuring head (41), the first annular fixed measuring head (42), the second fan-shaped fixed measuring head (51) and the second annular fixed measuring head (52), and the number of rotating turns n of the first rotating shaft (1) is obtained1And the first axis of rotation (1) in the range of [0,360 DEG N ] in multiple turns
2. The mechanical multiturn absolute time gate encoder of claim 1, wherein: the first rotating shaft (1) is a magnetic-conductive gear shaft, and the first gear (11) is a gear directly processed on the first rotating shaft; the second rotating shaft (2) is a gear shaft, and the second gear (21) and the third gear (22) are gears directly processed on the second rotating shaft (2); the third rotating shaft (3) is a magnetic-conductive gear shaft, and the fourth gear (31) is a gear directly processed on the third rotating shaft.
3. The mechanical multiturn absolute time gate encoder according to claim 1 or 2, characterized in that: obtaining the number n of turns of the first rotating shaft (1)1And the first axis of rotation (1) in the range of [0,360 DEG N ] in multiple turnsThe specific mode is as follows:
the signal processing system processes a multipole induction signal output by an induction coil on the first fan-shaped annular fixed measuring head (41) and a monopole induction signal output by an induction coil on the first annular fixed measuring head (42) to obtain an absolute angle theta of the first rotating shaft (1) within a single-turn range of [0,360 DEG ]1;
The signal processing system processes a multi-pole induction signal output by an induction coil on the second fan-shaped annular fixed measuring head (51) and a single-pole induction signal output by an induction coil on the second annular fixed measuring head (52) to obtain an absolute angle theta of the third rotating shaft (3) within a single-turn range of [0,360 DEG ]4;
The signal processing system utilizes the formula:calculating the number n of turns of the first rotating shaft (1)1(ii) a Wherein Floor () represents a down-rounding operation, Δ θ 'represents a first angle difference, and Δ θ' ═ θ1-θ4And K' represents a first cycle difference angle,
the signal processing system utilizes the formula:calculating the absolute angle of the first shaft (1) in a range of [0,360 DEG N ] turns
4. A mechanical multiturn absolute time gate encoder according to claim 2 or 3, wherein:
the signal processing system processes a multi-pole induction signal output by an induction coil on the first fan-shaped measuring head (41) to obtain a measured value beta' of a precise measurement angle when the first rotating shaft (1) rotates to a certain position;
the signal processing system processes the monopole induction signal output by the induction coil on the first annular fixed measuring head (42) to obtain a rough measurement angle measured value beta 'when the first rotating shaft (1) rotates to a certain position'0;
The signal processing system utilizes the formula:calculating the absolute angle theta of the first rotating shaft (1) within a single turn range of [0,360 DEG ]1;
The signal processing system processes a multi-pole induction signal output by an induction coil on the second fan-shaped measuring head (51) to obtain a measured value beta' of a precise measuring angle when the third rotating shaft (3) rotates to a certain position;
the signal processing system processes the unipolar induction signal output by the induction coil on the second annular fixed measuring head (52) to obtain a rough measured angle measured value beta' when the third rotating shaft (3) rotates to a certain position0;
The signal processing system utilizes the formula:calculating the third rotation axis (3)Absolute angle theta in the range of 0,360 DEG single turn4。
Background
Encoders are currently used as one of the sensor technologies, mainly for detecting the speed, position, angle, distance and counting of mechanical movements. The multi-turn absolute encoder can obtain information such as the current position immediately after power failure and power re-on, and zero-resetting is not needed. However, the multi-turn absolute encoder (for example, a battery multi-turn encoder depending on battery memory, a wiegand electronic multi-turn encoder depending on wiegand power generation micro-energy storage, etc.) on the market still needs to store information such as the current position by means of external energy, is not really power-off storage, and is not high in reliability. In contrast, the mechanical multi-turn absolute encoder can encode the mechanical position by using a plurality of sets of gear transmissions to acquire and store information such as the current position, but a large number of gear transmission stages can cause a large transmission error.
Disclosure of Invention
The invention aims to provide a mechanical multi-turn absolute time grating encoder, which is used for reducing transmission errors and improving measurement accuracy through a compact structure.
The invention relates to a mechanical multi-turn absolute time grating encoder which comprises a first rotating shaft, a second rotating shaft, a third rotating shaft, a first time grating angle sensing unit, a second time grating angle sensing unit and a signal processing system. The first rotating shaft is provided with a magnetic conductive first eccentric shaft neck, and the first rotating shaft is coaxially fixed with a gear number z1The second rotating shaft is coaxially fixed with a first magnetic-conductive gear, and the number of teeth is z2And a second gear and a number of teeth of z3The third rotating shaft is provided with a second magnetic conduction eccentric shaft neck, and the third rotating shaft is coaxially fixed with a gear number z4The first gear is meshed with the second gear, and the third gear is meshed with the fourth gear; wherein, let M be z1*z3,N=z2*z4M and N are each prime. The first time grating angle sensing unit comprises a first sector annular fixed measuring head and a first annular fixed measuring head, the first sector annular fixed measuring head is coaxially and laterally arranged on the outer side of the first gear, and a space is reserved between the first sector annular fixed measuring head and the first gearAnd the first annular measuring head is sleeved outside the first eccentric shaft neck, a gap is reserved between the first annular measuring head and the first eccentric shaft neck, and the axis of the first annular measuring head is superposed with the axis of the first rotating shaft. The second time grating angle sensing unit comprises a second fan-shaped fixed measuring head and a second annular fixed measuring head, the second fan-shaped fixed measuring head is coaxially arranged at the outer side of the fourth gear, a gap is reserved between the second fan-shaped fixed measuring head and the fourth gear, the second annular fixed measuring head is sleeved outside the second eccentric shaft neck, a gap is reserved between the second annular fixed measuring head and the second eccentric shaft neck, and the axis of the second annular fixed measuring head is superposed with the axis of the second rotating shaft; the first fan-shaped annular fixed measuring head, the first annular fixed measuring head, the second fan-shaped annular fixed measuring head and the second annular fixed measuring head are connected with the signal processing system.
The signal processing system generates an excitation signal to act on an excitation coil on the first fan-shaped fixed measuring head, an excitation coil on the first annular fixed measuring head, an excitation coil on the second fan-shaped fixed measuring head and an excitation coil on the second annular fixed measuring head, when the first rotating shaft rotates as a driving shaft, the second rotating shaft and the third rotating shaft rotate as driven shafts, the signal processing system processes an induction signal output by the induction coil on the first fan-shaped fixed measuring head, an induction signal output by the induction coil on the first annular fixed measuring head, an induction signal output by the induction coil on the second fan-shaped fixed measuring head and an induction signal output by the induction coil on the second annular fixed measuring head to obtain the number n of rotating turns of the first rotating shaft1And the first axis of rotation in the absolute angle in the range of [0,360 DEG N ] multiple turns
Preferably, the first rotating shaft is a magnetic gear shaft, and the first gear is a gear directly processed on the first rotating shaft; the second rotating shaft is a gear shaft, and the second gear and the third gear are gears directly processed on the second rotating shaft; the third rotating shaft is a magnetic-conductive gear shaft, and the fourth gear is a gear directly processed on the third rotating shaft.
When the first rotating shaft is used as a driving shaft,due to the transmission ratio of the first gear to the fourth gear(M and N satisfy a coprime relationship); therefore, when the first gear rotates N times (also the first rotating shaft rotates N times), the fourth gear rotates M times (also the third rotating shaft rotates M times), that is, when the first gear and the fourth gear start to rotate from a certain position and return to the same position at the same time, the difference of the rotation number of the first gear and the fourth gear is N-M times, which is said to complete a periodic movement. When the first gear rotates for 1 circle, the angular difference of the first gear minus the fourth gear is called as a first peripheral difference angle K',
from the above analysis, every 1 rotation of the first gear, the angular difference between the first gear and the fourth gear is increased by 1 first rotation angle K', and the first gear rotates n1The angular difference of the ring, the first gear and the fourth gear is n1K'; therefore, after the absolute angles of the first gear and the fourth gear within the range of [0,360 DEG ] single turn (also the absolute angles of the first rotating shaft and the third rotating shaft within the range of [0,360 DEG ]) are respectively measured by the first time grating angle sensing unit and the second time grating angle sensing unit, the number of turns n of the first rotating shaft can be obtained1And the first axis of rotation in the absolute angle in the range of [0,360 DEG N ] multiple turns
Preferably, the number n of turns of the first rotating shaft is obtained1And the first axis of rotation in the absolute angle in the range of [0,360 DEG N ] multiple turnsThe specific mode is as follows:
the signal processing system processes a multi-pole induction signal output by the induction coil on the first sector annular fixed measuring head and a single-pole induction signal output by the induction coil on the first annular fixed measuring head to obtain a first rotating shaft with a rotation angle of [0,360 DEG ]Absolute angle theta in the range of a single turn1. The signal processing system processes a multipole induction signal output by the induction coil on the second fan-shaped annular fixed measuring head and a monopole induction signal output by the induction coil on the second annular fixed measuring head to obtain an absolute angle theta of the third rotating shaft within a single-turn range of 0 and 360 DEG4。
The signal processing system utilizes the formula:calculating the number n of turns of the first rotating shaft1(ii) a Wherein Floor () represents a Floor operation,show taking downΔ θ' represents a first angle difference, Δ θ ═ θ1-θ4And K' represents a first cycle difference angle,the signal processing system utilizes the formula: calculating an absolute angle of the first shaft over a plurality of revolutions [0,360 DEG N ]
Because the first gear has a periodic tooth space structure, when the first gear relatively rotates with respect to the first sector annular measuring head, the induction coil on the first sector annular measuring head generates a periodic induction signal (which is a multi-pole induction signal) which changes with the position. Because the axis of the first eccentric shaft neck is parallel to the axis of the first circular ring-shaped fixed measuring head, the gap between the first eccentric shaft neck and the first circular ring-shaped fixed measuring head is not uniform, and the first eccentric shaft neck can generate regular air gap length change when rotating within a range of 360 degrees in a circle, when the first eccentric shaft neck rotates relative to the first circular ring-shaped fixed measuring head, an induction coil on the first circular ring-shaped fixed measuring head can generate periodic induction signals (which are unipolar induction signals) changing along with the position.
The signal processing system processes the multi-pole induction signal output by the induction coil on the first sector annular measuring head to obtain a measured value beta' of the accurate measurement angle when the first rotating shaft rotates to a certain position (namely the first gear rotates to a certain position). The signal processing system processes the unipolar induction signals output by the induction coil on the first circular ring-shaped fixed measuring head to obtain a rough measurement angle measured value beta 'when the first rotating shaft rotates to a certain position'0. Wherein is beta'0Has been preset by the signal processing system to [0,360 °), and the value range of beta' has been preset by the microprocessor toSimultaneously setting beta 'when the first rotating shaft is positioned at an absolute zero position'0β' ═ 0; the coarsely measured angle measurement value β 'when the first rotating shaft starts to rotate one turn from the absolute zero position relative to the first time grid angle sensing unit'0Change 1 time at [0,360 deg. ] C, and accurately measure angle measured value beta' atChange 1 time. The signal processing system utilizes the formula:calculating the absolute angle theta of the first rotating shaft within a single-turn range of [0,360 DEG ]1. Floor () represents a rounding down operation,show taking downThe integer part of (2).
Because the third gear has a periodic tooth space structure, when the third gear rotates relative to the second annular measuring head, the induction coil on the second annular measuring head generates a periodic induction signal (which is a multi-pole induction signal) which changes with the position. Because the axis of the second eccentric shaft neck is parallel to the axis of the second circular ring-shaped measuring head, the gap between the second eccentric shaft neck and the second circular ring-shaped measuring head is not uniform, and the second eccentric shaft neck can generate regular air gap length change when rotating within a range of 360 degrees in a circle, when the second eccentric shaft neck rotates relative to the second circular ring-shaped measuring head, an induction coil on the second circular ring-shaped measuring head can generate periodic induction signals (which are unipolar induction signals) changing along with the position.
The signal processing system processes the multi-pole induction signal output by the induction coil on the second fan-shaped measuring head to obtain a measured value beta' of the accurate measurement angle when the third rotating shaft rotates to a certain position (also the fourth gear rotates to a certain position). The signal processing system processes the monopole induction signal output by the induction coil on the second annular fixed measuring head to obtain a rough measurement angle measured value beta' when the third rotating shaft rotates to a certain position0. Wherein, beta ″)0Has been preset by the signal processing system to [0,360 °), the value range of β "has been preset by the microprocessor toWhile setting the third rotating shaft to be at the absolute zero position, beta ″)0β ═ 0; roughly measuring an angle measurement value beta' when the third rotating shaft rotates for one circle relative to the second time grating angle sensing unit from the absolute zero position0At [0,360 deg. ] C, 1 time, the measured value of the precision angle is inChange 1 time. The signal processing system utilizes the formula:calculating the absolute angle theta of the third rotating shaft within a single-turn range of [0,360 DEG ]4. Floor () represents a rounding down operation,show taking downThe integer part of (2).
The invention has the following effects:
(1) compared with the existing mechanical multi-turn absolute encoder, the multi-stage gear transmission is reduced to two-stage gear transmission, the absolute angle of the first rotating shaft within the range of [0,360 DEG ] single turn is measured by utilizing the first time grating angle sensing unit to be matched with the first gear and the first eccentric shaft neck, the absolute angle of the third rotating shaft within the range of [0,360 DEG ] single turn is measured by utilizing the second time grating angle sensing unit to be matched with the fourth gear and the second eccentric shaft neck, and the number of turns n of the first rotating shaft in rotation is further measured1And the first axis of rotation in the absolute angle in the range of [0,360 DEG N ] multiple turnsThe structure is more compact, and the transmission error is also less to measurement accuracy has been improved.
(2) Compared with an absolute encoder which depends on the internal memory of devices such as a battery, the absolute encoder which depends on self power-off storage in the true sense does not exist, and the situation that the devices such as the battery cannot work after power-off does not exist.
(3) Because the detection element is the first and the second time grating angle sensing units, the requirement on the working environment is low, and the work in extreme environments such as high-temperature/low-temperature environment, strong vibration, impact and the like can be realized.
Drawings
Fig. 1 is a schematic structural diagram of the present embodiment.
Fig. 2 is a schematic structural diagram of the first rotating shaft in this embodiment.
Fig. 3 is a schematic structural diagram of the second rotating shaft in the embodiment.
Fig. 4 is a schematic structural diagram of the third rotating shaft in this embodiment.
Fig. 5 is a schematic block diagram of signal processing in the present embodiment.
Detailed Description
In order to make the aforementioned structures, features, and advantages of the present invention comprehensible, specific examples accompanied with figures are described in detail below.
The mechanical multi-turn absolute time-grating encoder shown in fig. 1 to 5 includes a first rotating shaft 1, a second rotating shaft 2, a third rotating shaft 3, a first time-grating angle sensing unit 4, a second time-grating angle sensing unit 5, and a signal processing system.
As shown in fig. 2, the first rotating shaft 1 is a magnetic gear shaft, and a first gear 11 and a first eccentric journal 12 are machined on the first rotating shaft 1 (the first gear 11 and the first eccentric journal 12 are also magnetic). The axis of the first gear 11 coincides with the axis of the first rotating shaft 1, and the first gear 11 has a module of 0.7 and a number of teeth of 65 (i.e. z)165); the first eccentric journal 12 is a cylinder protruding 10mm on the first gear side (i.e., the axial length of the first eccentric journal 12 is 10mm), the axis of the first eccentric journal 12 is parallel to the axis of the first rotating shaft 1 and is offset by 1mm in the radial direction, the diameter of the first eccentric journal 12 is 20mm, and the diameter of the first eccentric journal 12 is smaller than the difference between the diameter of the root circle of the first gear 11 and the offset distance (i.e., 1 mm). The first gear 11 is preferably a standard spur gear.
As shown in fig. 3, the second rotating shaft 2 is a gear shaft (magnetic conductive or non-magnetic conductive), a second gear 21 and a third gear 22 are coaxially and alternately machined on the second rotating shaft 2, and both the axis of the second gear 21 and the axis of the third gear 22 are coincident with the axis of the second rotating shaft 2. The second gear 21 has a module of 0.7 and a tooth count of 64 (i.e., z)264) and the third gear 22 has a module of 0.7 and a number of teeth of 63 (i.e., z)363). The second gear 21 and the third gear 22 are preferably standard spur gears.
As shown in fig. 4, the third rotating shaft 3 is a magnetic gear shaft, and a fourth gear 31 and a second eccentric journal 32 are machined on the third rotating shaft 3 (the corresponding fourth gear 31 and the second eccentric journal 32 are also magnetic). The axis of the fourth gear 31 coincides with the axis of the third rotating shaft 3, and the module of the fourth gear 31 is 0.7 and the number of teeth is 64 (i.e. z)464); second eccentric journal 32In order to form a cylinder protruding 11mm on the fourth gear side (i.e., the axial length of the second eccentric journal 32 is 11mm), the axis of the second eccentric journal 32 is parallel to the axis of the third rotating shaft 3 and is offset by 1mm in the radial direction, the diameter of the second eccentric journal 32 is 20mm, and the diameter of the second eccentric journal 32 is smaller than the difference between the diameter of the root circle of the fourth gear 31 and the offset distance (i.e., 1 mm). The fourth gear 31 is preferably a standard spur gear.
As shown in fig. 1, the first gear 11 is engaged with the second gear 21 and is installed with its center planes overlapped at a standard center distance. The third gear 22 is engaged with the fourth gear 31 and is installed with a standard center distance with its center planes overlapped. M ═ z1*z3=4095,N=z2*z44096, 4095 and 4096 satisfy a coprime relationship.
As shown in fig. 1 and 5, the first time grid angle sensing unit 4 includes a first sector annular fixed measuring head 41 and a first annular fixed measuring head 42, the first sector annular fixed measuring head 41 has a plurality of teeth wound with an excitation coil and an induction coil, and the first annular fixed measuring head 42 has a plurality of teeth wound with an excitation coil and an induction coil. The first sector annular measuring head 41 is coaxially arranged beside the first gear 11, a gap is reserved between the first sector annular measuring head 41 and the first gear 11, and the central plane of the first sector annular measuring head 41 and the central plane of the first gear 11 are located on the same plane. The first annular measuring head 42 is sleeved outside the first eccentric shaft neck 12, a gap is reserved between the first annular measuring head 42 and the first eccentric shaft neck 12, the central plane of the first annular measuring head 42 and the central plane of the first eccentric shaft neck 12 are located on the same plane, and the axis of the first annular measuring head 42 is overlapped with the axis of the first rotating shaft 1. The second time grating angle sensing unit 5 includes a second sector annular fixed measuring head 51 and a second annular fixed measuring head 52, the second sector annular fixed measuring head 51 has a plurality of teeth wound with exciting coils and induction coils, and the second annular fixed measuring head 52 has a plurality of teeth wound with exciting coils and induction coils. The second sector annular measuring head 51 is coaxially arranged beside the fourth gear 31, a gap is reserved between the second sector annular measuring head 51 and the fourth gear 31, and the central plane of the second sector annular measuring head 51 and the central plane of the fourth gear 31 are positioned on the same plane. The second annular measuring head 52 is sleeved outside the second eccentric shaft neck 32, a gap is left between the second annular measuring head 52 and the second eccentric shaft neck 32, the central plane of the second annular measuring head 52 and the central plane of the second eccentric shaft neck 32 are located on the same plane, and the axis of the second annular measuring head 52 is overlapped with the axis of the second rotating shaft 2.
The signal processing system comprises an analog filter circuit, a first amplification filter circuit, a second amplification filter circuit, a third amplification filter circuit, a fourth amplification filter circuit and a microprocessor, wherein the microprocessor generates an excitation signal which passes through the analog filter circuit and then acts on an excitation coil on the first fan-shaped fixed measuring head 41, an excitation coil on the first annular fixed measuring head 42, an excitation coil on the second fan-shaped fixed measuring head 51 and an excitation coil on the second annular fixed measuring head 52. When the first rotating shaft 1 rotates as a driving shaft and the second rotating shaft 2 and the third rotating shaft 3 rotate as driven shafts, that is, when the first rotating shaft 1 rotates as a driving shaft, the first eccentric journal 12 rotates, the first gear 11 rotates to drive the second gear 21 to rotate, the second gear 21 rotates to drive the second rotating shaft 2 to rotate, the second rotating shaft 2 rotates to drive the third gear 22 to rotate, the third gear 22 rotates to drive the fourth gear 31 to rotate, and the fourth gear 31 rotates to drive the third rotating shaft 3 and the second eccentric journal 32 to rotate, the induction coil on the first fan-shaped annular measuring head 41 outputs a periodically-changing multi-pole induction signal, and the signal is amplified and filtered by the first amplifying and filtering circuit and then is input into the microprocessor; the induction coil on the first annular fixed measuring head 42 outputs a periodically-changed single-pole induction signal, and the single-pole induction signal is amplified and filtered by the second amplification and filtering circuit and then is input into the microprocessor; the induction coil on the second fan-shaped annular fixed measuring head 51 outputs a multi-pole induction signal which changes periodically, and the multi-pole induction signal is amplified and filtered by a third amplifying and filtering circuit and then is input into the microprocessor; the induction coil on the second circular shape fixed measuring head 52 outputs a periodically changing single-pole induction signal, and the single-pole induction signal is amplified and filtered by the fourth amplifying and filtering circuit and then is input into the microprocessor.
The microprocessor compares the signal input from the first amplifying filter circuit with the excitation signal, the phase difference is represented by the number of the interpolated high-frequency clock pulses, and the measured value beta of the accurate measurement angle when the first rotating shaft 1 rotates to a certain position is obtained through conversion'. The microprocessor compares the signal input from the second amplification filter circuit with the excitation signal, and converts the phase difference to a rough measurement angle measurement value beta 'when the first rotor shaft 1 rotates to a certain position, the phase difference being represented by the number of interpolated high-frequency clock pulses'0(ii) a Wherein is beta'0Has been preset by the microprocessor to a value range of [0,360 ] (i.e., 0 ≦ β'0Less than 360 degrees, the value range of beta' is preset by a microprocessor(i.e. the) Simultaneously setting beta 'when the first rotating shaft 1 is located at the absolute zero position'0β' ═ 0; the rough angle measurement β 'is measured when the first rotor shaft 1 is rotated by one revolution relative to the first time-grid angle sensor unit 4 from the absolute zero position'0Change 1 time at [0,360 deg. ] C, and accurately measure angle measured value beta' atChange 1 time. The microprocessor utilizes the formula:calculating the absolute angle theta of the first rotating shaft 1 within a single-turn range of 0,360 DEG1(ii) a Floor () represents a rounding down operation,show taking downThe integer part of (2).
The microprocessor compares the signal input from the third amplifying and filtering circuit with the excitation signal, the phase difference is represented by the number of interpolated high-frequency clock pulses, and the phase difference is converted to obtain a measured value beta' of the accurate measurement angle when the third rotating shaft 3 rotates to a certain position; the microprocessor compares the signal input from the fourth amplifying and filtering circuit with the excitation signal, and the phase difference is determined by the interpolated high frequencyThe number of the clock pulses is expressed and converted to obtain a rough measured angle value beta' when the third rotating shaft 3 rotates to a certain position0(ii) a Wherein, beta ″)0The value range of (b) is preset to be [0,360 DEG ] (i.e. 0 is not less than beta ″)0< 360 deg.), the value range of beta "has been preset by the microprocessor(i.e. the) While setting the third rotating shaft 3 to be at the absolute zero position, beta ″)0β ═ 0; when the third rotating shaft 3 rotates one turn from the absolute zero position relative to the second time grating angle sensing unit 5, the angle measurement value beta' is roughly measured0At [0,360 deg. ] C, 1 time, the measured value of the precision angle is inChange 1 time. The microprocessor utilizes the formula:calculating the absolute angle theta of the third rotating shaft 3 within a single turn range of 0,360 DEG4. Floor () represents a rounding down operation,show taking downThe integer part of (2).
Obtaining the absolute angle theta of the first rotating shaft 1 within a single turn range of 0,360 DEG1And the absolute angle theta of the third rotary shaft 3 within a single turn range of 0,360 DEG4The microprocessor then uses the formula:calculating the number n of turns of the first rotating shaft 11(ii) a Wherein Floor () represents a Floor operation,show taking downΔ θ' represents a first angle difference, Δ θ ═ θ1-θ4And K' represents a first cycle difference angle,the microprocessor utilizes the formula:calculating the absolute angle of the first rotating shaft 1 within a plurality of turns of [0,1474560 DEG ]The microprocessor outputs the number n of turns of the first rotating shaft 1 according to subsequent requirements1And/or the absolute angle of the first axis of rotation 1 over a plurality of revolutions at [0,1474560 DEG ]
Similarly, in this embodiment, the number of turns n of the third rotating shaft 3 can be calculated4And the third shaft 3 in a multiple-turn range of [0,1474200 ° (i.e., [0,360 °. M)) ]
Since the fourth gear 31 rotates 4095 turns (also the third rotating shaft 3 rotates 4095 turns) when the first gear 11 rotates 4096 turns (also the first rotating shaft 1 rotates 4096 turns), that is, when the first gear 11 and the fourth gear 31 start to rotate from a certain position and return to the same position at the same time, the fourth gear 31 and the first gear 11 are different by 1 turn, which is said to complete a periodic movement.
When the fourth gear 31 rotates 1 turn, the angular difference between the fourth gear 31 and the first gear 11 is called a second peripheral angle K ",(negative values).
Every 1 rotation of the fourth gear 31, the angular difference between the fourth gear 31 and the first gear 11 is increased by 1 second circumferential angle K', and the fourth gear 31 rotates n4The angular difference between the ring and the fourth gear 31 minus the first gear 11 is n4*K″。
The microprocessor utilizes the formula:calculating the number n of turns of the third rotating shaft 34(ii) a Wherein Floor () represents a Floor operation,show taking downΔ θ "represents the second angle difference, and Δ θ ″, θ4-θ1(negative values). The microprocessor utilizes the formula:calculating the absolute angle of the third rotating shaft 3 within a plurality of turns of [0,1474200 DEG ]