Encoder system based on inductive encoder chip

Abstract

The invention provides an encoder system based on an inductance type encoder chip. The inductance type encoder system is characterized in that the inductance type encoder system is composed of a rotating motor (1), a rotor PCB (2), a coil PCB (3) and an encoder circuit board (4), the coil PCB (3) is composed of a transmitting coil (31) and a receiving coil array (32), and the encoder circuit board (4) is composed of an inductance type encoder chip (41), an encoder chip peripheral working circuit (42), a signal receiving and processing chip (43) and a data output interface driving circuit (44). Wherein the multipath receiving inductance type encoder chip (41) is composed of a transmitting coil driving circuit (411), a receiving coil demodulation circuit (412), a receiving signal feedback circuit (413) and an interface driving circuit (414). The device can be used for measuring the rotation angle, the rotation speed and the rotor state of the motor, and can be widely applied to the fields of industrial robots, automotive electronics, medical treatment, national defense, aerospace and the like.

Description

(I) Technical field

[0001] The present invention relates to an encoder system based on an inductive encoder chip, which is widely used in automotive electronics, medical treatment, industrial robots, national defense, aerospace and other fields, and belongs to the field of inductive sensor technology. (II) Background technology

[0002] Inductive encoders, also known as inductive encoders, are advanced sensors that use eddy current induction technology for non-contact position detection. This encoder does not rely on the copper coils in traditional rotary encoders as the rotor and induction coil design, but uses densely arranged coil windings and copper sheets on a printed circuit board (PCB) to achieve the rotor design. Thanks to this design, inductive encoders have a thinner volume, lighter weight, lower energy consumption, and higher measurement accuracy. Compared with optical encoders, inductive encoders can maintain stable measurement performance in harsh environments. With the continuous advancement of inductive encoder technology, it plays an increasingly important role in the field of modern sensing and control, measuring mechanical motion through the principle of electromagnetic induction. At present, inductive encoder technology is developing in the direction of miniaturization, high precision, wide application, integration, and intelligence.

[0003] Due to its ability to work in harsh environments and relatively high precision, inductive encoders have a wide range of use scenarios, such as for measuring the angle of robotic arms in the field of industrial robots, for steering wheel torque angle measurement, motor speed measurement, etc. in the field of automotive electronics, and for position movement measurement in the field of machine tools. However, its application is still limited by installation issues. The main reason is that the coil and the rotor are non-contact. While providing convenience, it also introduces the problem of the influence of the relative position of the coil and the rotor on the induction of the receiving coil. When the distance between the coil and the rotor is too far in some scenarios, or an angle deviation occurs during installation, the receiving coil induction will produce errors, and when the rotor is subjected to external pressure and changes in ambient temperature during use, the dense coil windings on the rotor will produce certain deformations, causing the receiving coil to produce corresponding errors. These problems greatly affect the measurement accuracy. At present, the most commonly used solution is to add an automatic gain control (AGC) circuit or a digital programmable gain control circuit to the rear of the receiving coil demodulation circuit inside the inductive encoder. However, this solution will cause additional delays. Under ultra-high speed conditions, this delay will affect the measurement accuracy and measurement results, and precise feedback control cannot be completed. At the same time, the errors caused by some special installation problems cannot be well solved.

[0004] The present invention analyzes the relationship between the rotor and the coil, and confirms through formula derivation that the biggest factors affecting the demodulation waveform quality of the receiving coil are the receiving coil area and the physical distance between the receiving coil and the transmitting coil. In view of this problem, a solution different from increasing the delay to adjust the gain is adopted, and the adjustment is made from the source transmitting coil, which greatly reduces the delay problem introduced by the automatic gain control. At the same time, the receiving coil adopts a coil array method to calculate the difference in induction between the coils, and the current state of the rotor can be obtained by calculation. The installation of the rotor can be fine-tuned by the feedback position information, or compensation can be added based on the position information to eliminate the influence of the deformation of the rotor on the model during operation, thereby further improving the accuracy. The traditional inductive encoder chip has a large restriction on the coil area. Generally, the chip is only for a specific area range and cannot be applied to coils of multiple sizes at the same time. In different usage scenarios, it is necessary to design multiple chips, resulting in an increase in cost. The inductive encoder chip included in the present invention is different from the traditional receiving signal demodulation and AGC adjustment. It adopts the method of analyzing the receiving signal waveform and feedback adjustment of the transmitting coil parameters. At the same time, through its programmable characteristics, the distribution of the coils in the positive and reverse directions of the receiving coil array is adjusted to adapt to different rotors. The robustness in multiple usage scenarios and unstable usage scenarios is increased. (III) Summary of the invention

[0005] The present invention aims to provide an encoder system based on an inductive encoder chip, comprising a rotating motor (1), a rotor PCB (2), a coil PCB (3), and an encoder circuit board (4), wherein the coil PCB (3) comprises a transmitting coil (31) and a receiving coil array (32), the encoder circuit board (4) comprises an inductive encoder chip (41), an encoder chip peripheral working circuit (42), a signal receiving processing chip (43), and a data output interface driving circuit (44), wherein the multi-channel receiving inductive encoder chip (41) comprises a transmitting coil driving circuit (411), a receiving coil demodulation circuit (412), a receiving signal feedback circuit (413), and an interface driving circuit (414).

[0006] The object of the present invention is achieved in that:

[0007] The rotating motor (1) drives the rotor PCB (2) to rotate. The two are connected by a rotating shaft to ensure the synchronization of rotation. The coil PCB (3) is driven by the encoder circuit board (4). At this time, the rotor PCB (2) and the coil PCB (3) generate induced electromotive force on the receiving coil array (32) due to the eddy current effect, and transmit the signal with the rotor position information to the encoder circuit board (4). The signal is received by the inductive encoder chip (41). The signal is demodulated into a sine and cosine signal with the rotor position information by the receiving coil demodulation circuit (412) inside the chip and sent to the receiving signal feedback circuit (413) for processing and analysis. After the corresponding characteristics are adjusted, the parameters of the transmitting coil drive circuit (411) are adjusted to make the system in a more optimal working state. At the same time, the signal drive output is sent to the signal receiving processing chip (43) through the output signal drive circuit (414) for calculation and processing into more intuitive data. After that, the interface drive circuit (44) outputs the data through the communication protocol for use by the subsequent circuit to control the rotating motor (1) and achieve the effect of closed-loop control.

[0008] The transmitting coil (31) and the receiving coil array (32) in the coil PCB (3) in the system are in the form of PCB coil windings to form the transmitting coil, thereby eliminating the influence of installation errors of the receiving and transmitting coils, wherein the receiving coil array (32) is regularly arranged in the free space inside the coil winding formed by the transmitting coil (31), and the specifications of the receiving coil array (32) can be 2×2, 3×3, 4×4, etc. according to the size and shape of the rotor PCB (2), and can support up to 10×10. The more receiving coil arrays, the higher the accuracy. The coil windings of each coil are drawn on both sides of the PCB, which are equivalent to two coils in opposite directions.

[0009] The inductive encoder chip (41) has a programmable register for controlling the series and parallel connection of receiving multiple receiving coil input signals, and is adapted to various application scenarios by this method; since the rotor PCB (2) has a copper sheet with a special shape, the copper sheet generates an eddy current electric field due to the eddy current effect under the influence of the magnetic field generated by the transmitting coil (31), and the electric field generates a magnetic field in the opposite direction to the original magnetic field, offsetting a part of the original magnetic field, thereby causing the inductance, impedance and quality factor of the coil to change; during the rotation process, the forward coil and the reverse coil are blocked, and the Due to the different areas of the blocked coils, the induced electromotive forces generated by the completely blocked forward and reverse coils will be offset due to the opposite reasons, and the voltage input to the receiving coil demodulation circuit (412) will be 0V. However, the induced electromotive forces generated by the forward and reverse coils that are not completely blocked cannot be offset, and the corresponding voltage will be generated and then demodulated by the receiving coil demodulation circuit (412) and input to the receiving signal feedback circuit (413). The self-inductance of the receiving coil and the transmitting coil is not fixed, but is affected by the rotor PCB (2). The influencing factor formula is:

[0010] Where L is the receiving coil self-inductance, δ is the air gap length, and μ is the air magnetic permeability, which is a fixed value of 4π*10 -7 H / m, S is the cross-sectional area of ​​the air gap. From the formula, it can be seen that the receiving coil is affected by the position of the rotor PCB (2), where the coverage area S and the air gap length δ are influencing factors. The relationship between the induced voltage at the receiving coil and the induced voltage at the transmitting coil is affected by the mutual inductance. The mutual inductance electromotive force at the receiving coil is

[0011] Where ε is the induced electromotive force, Ψ 12 is the magnetic flux linkage of the induction coil. I1 is the current of the transmitting coil. Due to the mutual inductance between the transmitting circuit and the receiving circuit, there is a fixed parasitic resistance in the receiving circuit, and its current is affected by the voltage. The calculation formula of the mutual inductance coefficient M is:

[0012] Where M is the mutual inductance, k is the coupling factor, L1 is the inductance of the transmitting coil, and L2 is the inductance of the receiving coil. Therefore, the main factors affecting the induced electromotive force of the receiving coil are the air gap length δ and the coverage area S.

[0013] Since the induced electromotive force of the receiving coil is affected by the air gap δ, when all the coils of the inductive encoder chip (41) are configured to be forward or reverse, the target induced electromotive force can be calculated by setting the target air gap value, and the error between the target electromotive force and the actual electromotive force can be obtained by subtracting each other. By calculating the errors of multiple induction coils, the distance and angle deviation of the rotor PCB (2) relative to the target position can be obtained; through this distance value and deviation, the parameters of the transmitting coil drive circuit (411) can be fed back to the transmitting coil drive circuit (411) to adjust the peak-to-peak value Vpptx of the transmitting coil AC signal, thereby affecting the transmitting coil current I1, so that the peak-to-peak value max (Vpprx) of the signal received by the receiving coil demodulation circuit (412) remains stable. Specifically, the receiving demodulation circuit (412) inputs the peak-to-peak value of the received signal max(Vpprx) into the receiving signal feedback circuit (413), and the circuit makes a judgment. If max(Vpprx) is greater than the reference peak-to-peak value (Vppref), the value of the coefficient K input to the transmitting coil driving circuit (411) is reduced; if max(Vpprx) is less than the reference peak-to-peak value (Vppref), the value of the coefficient K input to the transmitting coil driving circuit (411) is increased; if they are equal, K remains unchanged; data can also be output through the interface driving circuit (44) through the communication protocol for use by the subsequent circuit, so as to adjust the relative position between the rotor PCB (2) and the coil PCB (3).

[0014] The induced electromotive force of the receiving coil is affected by the coverage area S. Therefore, in different usage scenarios, different coil sizes will affect the mutual inductance electromotive force at the receiving coil. In extreme cases where the area required for high-precision scenarios is too large or too small, ordinary inductive encoder chips cannot fully meet the working requirements, resulting in reduced accuracy or failure to work. At this time, the inductive encoder chip used in this patent with a receiving coil demodulation circuit (412) and a receiving signal feedback circuit (413) that can support multiple receiving coil inputs can automatically adjust the transmission power at the transmitting coil, and can also configure the receiving coil array (32) according to different rotor configurations. The forward and reverse coils are connected in series and parallel. The induced electromotive force of the receiving coil can be automatically adjusted to achieve the preset accuracy of the chip in the case where it is too weak or too strong. First, the coil area is estimated according to the usage scenario, and the coil area is divided into 4 ranges to preset different circuit initial parameters K0 to achieve applicability under various areas, as well as universality in various situations such as fan-shaped, annular, and linear shapes. (IV) Description of the drawings

[0018] Figure 1The invention is a schematic diagram of the structure of an encoder system based on an inductive encoder chip. The inductive encoder system is composed of a rotating motor (1), a rotor PCB (2), a coil PCB (3), and an encoder circuit board (4), wherein the coil PCB (3) is composed of a transmitting coil (31) and a receiving coil array (32), and the encoder circuit board (4) is composed of an inductive encoder chip (41), an encoder chip peripheral working circuit (42), a signal receiving processing chip (43), and a data output interface driving circuit (44), wherein the multi-channel receiving inductive encoder chip (41) is composed of a transmitting coil driving circuit (411), a receiving coil demodulation circuit (412), a receiving signal feedback circuit (413), and an interface driving circuit (414).

[0019] Figure 2 The schematic diagram is a principle diagram of system measurement in the first embodiment of the encoder system based on the inductive encoder chip. The system is composed of a rotor PCB (1), a coil PCB (2), and a rotor PCB target position (3), and the coil PCB is composed of a transmitting coil (21) and a receiving coil array (22). The dotted lines with arrows in the figure represent the distances from different positions on the rotor PCB (1) to the coil PCB (2).

[0020] Figure 3 It is a flow chart of an encoder system method based on an inductive encoder chip. The key process is divided into steps S1-S6. Through the internal adjustment of the inductive encoder chip, different rotor PCBs and coil PCBs are adapted, and finally the installation error of the rotor PCB and the coil PCB is reduced, thereby improving the accuracy of the system.

[0021] Figure 4 It is a schematic diagram of the position relationship between the coil PCB and the rotor PCB. The rotor PCB can rotate and be in different positions, while the coil PCB is relatively fixed. Different positions correspond to different receiving coil self-inductances L2, and therefore have different mutual inductance coefficients M. As a result, the induced electromotive force at the receiving coil changes with position. This change information includes the position information of the rotor. By analyzing this information, information such as the motor rotation position and rotation speed can be obtained. (V) Specific implementation methods Embodiment 1: Figure 2A functional schematic diagram for measuring the relative installation position of a rotor PCB (1) and a coil PCB (2) is provided. The coil PCB (1) is a round piece of all-metal material used to generate eddy current coupling between the coil and the rotor so that the induction coil array can better obtain the rotor PCB (1) and the induced electromotive force. After demodulation by the receiving demodulation circuit inside the inductive encoder, the signal is output by the output drive circuit to the subsequent signal receiving and processing chip FPGA for careful comparison, and the relative position is obtained and then output to the subsequent stage through the interface drive circuit due to installation adjustment, and at the same time, the corresponding initial parameter K0 of the corresponding transmitting coil drive circuit is generated. Figure 3 A flow chart of an encoder system method based on an inductive encoder chip is given, comprising the following steps: In S1, the rotor PCB and coil PCB are designed according to the needs of the usage scenario. After the design is completed, the rotating motor and various circuits and PCBs are deployed, and the approximate value of the designed receiving coil area S is recorded. The transmitting coil is a multi-turn ring coil, which forms a transmitting loop with the transmitting drive circuit. The calculation formula of the transmitting coil self-inductance coefficient L1 is Set the target distance between the rotor PCB and the coil PCB. The distance between the two PCBs is the air gap δ. The self-inductance coefficient L2 of each coil in the entire receiving coil array can be obtained by the formula: The calculated self-inductance coil coefficients L1 and L2 are calculated by the mutual inductance coefficient M formula Calculate the self-inductance coefficient M, and then set the initial parameter K0 of the transmitting coil. The selection relationship of this value is: Where A, B, C, and D are calculated and experimentally corrected empirical values, which are stored inside the chip. The chip selects this value by matching the external circuit parameters according to the receiving coil area S. The transmitting coil current I1 is obtained by the value of K0. Since the mutual inductance electromotive force at the receiving coil is By calculation, the value ε of the induced electromotive force output by the receiving coil when the rotor PCB is at the target position can be obtained. In S2, the rotary motor is controlled to rotate, and the inductive encoder chip circuit initialization work is started. In S3, the internal registers of the programmable encoder chip are configured through the signal receiving and processing chip FPGA. First, in order to measure the deviation between the actual installation of the rotor and the target position, the 3×3 receiving coil arrays are all configured to be in the same direction, and each pair of coils are connected in series. In S4, the initial parameter K0 of the transmitting coil set in S1 is configured into the corresponding register to complete the initialization of the encoder chip. The voltage Vpprx is continuously received by the receiving coil. The internal feedback circuit of the chip selects the maximum value maxVpprx in this period and calculates the change value ΔK of the transmitting coil parameter. When the transmitting coil drive circuit receives the parameter, it changes the transmitting coil drive and returns the adjusted K value to the signal receiving processing chip FPGA to calculate the value of the induced electromotive force at the current target position. In S5, the 9 induced electromotive forces generated by the receiving coil array obtained by the encoder chip are output to the FPGA for calculation and processing; The FPGA in S6 subtracts the values ​​of the 9 induced electromotive forces from the induced electromotive force calculated at the target position to obtain a relative position relationship of the current rotor PCB relative to the target position. This position relationship can be fed back to the post-processing during the rotor installation process, and the position of the coil PCB can be fine-tuned to approach the target position, thereby reducing the installation error in the encoder system and improving the accuracy of the encoder system. Embodiment 2: Figure 4 A simple design of inductive encoder coils and a position of the rotor PCB are given. The 2×2 receiving coil array is divided into two groups RX1 and RX2 through the registers allocated to the programmable encoder chip to control the coils. The two groups of receiving coils are designed with a phase difference of 90°. Each group of coils is divided into two coils of different polarity connected in series. In the absence of a rotor PCB, the positive and negative phases of the receiving coil cancel each other out, and the induced voltage value is 0V. When a rotor PCB is present, since the rotor PCB contains magnetic copper foil and is specially designed in shape, it rotates simultaneously with the rotating motor. When it rotates to the angle shown in the figure, the shaded part is the rotor PCB, and the positive induction value of the RX1 coil is the maximum value, and the negative induction value is 0. At this time, the RX1 coil senses the maximum electromotive force maxε. When the rotor rotates 180 degrees, the RX1 coil senses the minimum electromotive force minε. At this time Vpprx=maxε-minε Ideally, this formula can be derived as Vpprx = 2maxε = Vppref. The inductive encoder chip adjusts the internal feedback circuit parameters to make the actual measurement close to this value. In some embodiments, the coil and PCB are designed to be annular, or a group of coils includes multiple positive coils and negative coils, and the positive coil is equal to the negative coil. When the specific implementation includes 9 positive coils and negative coils, it can be understood that one circle outputs 9 dot cycles. Among them, the RX1 coil includes RX10p, RX11p, RX12p, RX13p, RX14p, RX15p, RX16p, RX17p, RX18p, RX10n, RX11n, RX12n, RX13n, RX14n, RX15n, RX16n, RX17n, RX18n, and the maximum electromotive force to which the cognac is subjected during the rotation of the rotor PCB is maxε=RX10p+RX11p+RX12p+RX13p+RX14p+RX15p+RX16p+RX17p+RX18p At this time, it is the sum of all positive polarity coils. At this time, considering the area factor, it is also the sum of the areas of all small coils. After selecting the corresponding parameter K0 according to the sum of the areas in step S3, the system works normally. During the operation of the system, the air gap between the rotor PCB and the coil PCB is automatically adjusted to more accurately reflect the current rotation position and speed.

Claims

1. An encoder system based on an inductive encoder chip. Its characteristics are: The inductive encoder system is composed of a rotating motor (1), a rotor PCB (2), a coil PCB (3), and an encoder circuit board (4), wherein the coil PCB (3) is composed of a transmitting coil (31) and a receiving coil array (32), and the encoder circuit board (4) is composed of an inductive encoder chip (41), an encoder chip peripheral working circuit (42), a signal receiving processing chip (43), and an interface driving circuit (44), wherein the multi-channel receiving inductive encoder chip (41) is composed of a transmitting coil driving circuit (411), a receiving coil demodulation circuit (412), a receiving signal feedback circuit (413), and an output signal driving circuit (414); in the system, the rotating motor (1) drives the rotor PCB (2) to rotate, and the two are connected through a rotating shaft to ensure the synchronization of rotation, and the coil PCB (3) is driven by the encoder circuit board (4), and the rotating motor (1) drives the rotor PCB (2) to rotate. The sub-PCB (2) and the coil PCB (3) generate induced electromotive force on the receiving coil array (32) due to the eddy current effect, and transmit the signal with the rotor position information to the encoder circuit board (4). The signal is received by the inductive encoder chip (41), and the signal is demodulated into a sine and cosine signal with the rotor position information by the receiving coil demodulation circuit (412) inside the chip and sent to the receiving signal feedback circuit (413) for processing and analysis. After that, the parameters of the transmitting coil drive circuit (411) are adjusted according to the corresponding characteristics, so that the system is in a more optimal working state. At the same time, the signal drive output is sent to the signal receiving processing chip (43) through the output signal drive circuit (414) for calculation and processing into more intuitive data. After that, the interface drive circuit (44) outputs the data through the communication protocol for use by the subsequent circuit to control the rotating motor (1), thereby achieving a closed-loop control effect.

2. The encoder system based on the inductive encoder chip according to claim 1; characterized in that: The transmitting coil (31) and the receiving coil array (32) in the coil PCB (3) in the system are used as transmitting coils in the form of PCB coil windings, thereby eliminating the influence of installation errors of the receiving and transmitting coils. The receiving coil array (32) is regularly arranged in the spare part inside the coil winding formed by the transmitting coil (31). The specifications of the receiving coil array (32) can be 2×2, 3×3, 4×4, etc. according to the size and shape of the rotor PCB (2), and can support up to 6×6. The more receiving coil arrays, the higher the accuracy. The coil windings of each coil are drawn on both sides of the PCB, which are equivalent to two coils in opposite directions.

3. The encoder system based on the inductive encoder chip according to claim 1; characterized in that: The inductive encoder chip (41) has a programmable register for controlling the series and parallel connection of receiving multiple receiving coil input signals, and is adapted to various application scenarios by this method; since the rotor PCB (2) has a copper sheet with a special shape, the copper sheet generates an eddy current electric field due to the eddy current effect under the influence of the magnetic field generated by the transmitting coil (31), and the electric field generates a magnetic field in the opposite direction to the original magnetic field, offsetting a part of the original magnetic field, thereby causing the inductance, impedance and quality factor of the coil to change; during the rotation process, the forward coil and the reverse coil are blocked. Since the areas of the blocked coils are different, the induced electromotive forces generated by the completely blocked forward and reverse coils will be offset due to the opposite reasons, and the voltage input to the receiving coil demodulation circuit (412) will be 0V. However, the induced electromotive forces generated by the forward and reverse coils that are not completely blocked cannot be offset, and the corresponding voltage will be generated and then demodulated by the receiving coil demodulation circuit (412) and input to the receiving signal feedback circuit (413). The self-inductance of the receiving coil and the transmitting coil is not fixed, but is affected by the rotor PCB (2). The influencing factor formula is: Where L is the receiving coil self-inductance, δ is the air gap length, and μ is the air magnetic permeability, which is a fixed value of 4π*10 -7 H / m, S is the cross-sectional area of ​​the air gap. From the formula, it can be seen that the receiving coil is affected by the position of the rotor PCB (2), where the coverage area S and the air gap length δ are influencing factors. The relationship between the induced voltage at the receiving coil and the induced voltage at the transmitting coil is affected by the mutual inductance. The mutual inductance electromotive force at the receiving coil is Where ε is the induced electromotive force, Ψ 12 is the magnetic flux linkage of the induction coil. I1 is the current of the transmitting coil. Due to the mutual inductance between the transmitting circuit and the receiving circuit, there is a fixed parasitic resistance in the receiving circuit, and its current is affected by the voltage. The calculation formula of the mutual inductance coefficient M is: Where M is the mutual inductance, k is the coupling factor, L1 is the inductance of the transmitting coil, and L2 is the inductance of the receiving coil. Therefore, the main factors affecting the induced electromotive force of the receiving coil are the air gap length δ and the coverage area S.

4. The encoder system based on the inductive encoder chip according to claim 3 is characterized in that: Since the induced electromotive force of the receiving coil is affected by the air gap δ, when all the coils of the inductive encoder chip (41) are configured to be forward or reverse, the target induced electromotive force can be calculated by setting the target air gap value, and the error between the target electromotive force and the actual electromotive force can be obtained by subtracting each other. By calculating the errors of multiple induction coils, the distance and angle deviation of the rotor PCB (2) relative to the target position can be obtained; through this distance value and deviation, the parameters of the transmitting coil drive circuit (411) can be fed back to the transmitting coil drive circuit (411) to adjust the peak-to-peak value Vpptx of the transmitting coil AC signal, thereby affecting the transmitting coil current I1, so that the peak-to-peak value max (Vpprx) of the signal received by the receiving coil demodulation circuit (412) remains stable. Specifically, the receiving demodulation circuit (412) inputs the peak-to-peak value of the received signal max(Vpprx) into the receiving signal feedback circuit (413), and the circuit makes a judgment. If max(Vpprx) is greater than the reference peak-to-peak value (Vppref), the value of the coefficient K input to the transmitting coil driving circuit (411) is reduced; if max(Vpprx) is less than the reference peak-to-peak value (Vppref), the value of the coefficient K input to the transmitting coil driving circuit (411) is increased; if they are equal, K remains unchanged; data can also be output through the interface driving circuit (44) through the communication protocol for use by the subsequent circuit, so as to adjust the relative position between the rotor PCB (2) and the coil PCB (3).

5. The encoder system based on the inductive encoder chip according to claim 3; characterized in that: The induced electromotive force of the receiving coil is affected by the coverage area S. Therefore, in different usage scenarios, different coil sizes will affect the mutual inductance electromotive force at the receiving coil. In extreme cases where the area required for high-precision scenarios is too large or too small, ordinary inductive encoder chips cannot fully meet the working requirements, resulting in reduced accuracy or failure to work. At this time, the inductive encoder chip used in this patent with a receiving coil demodulation circuit (412) and a receiving signal feedback circuit (413) that can support multiple receiving coil inputs can automatically adjust the transmission power at the transmitting coil, and can also configure the receiving coil array (32) according to different rotor configurations. The forward and reverse coils are connected in series and parallel. The induced electromotive force of the receiving coil can be automatically adjusted to achieve the preset accuracy of the chip in the case where it is too weak or too strong. First, the coil area is estimated according to the usage scenario, and the coil area is divided into 4 ranges to preset different circuit initial parameters K0 to achieve applicability under various areas, as well as universality in various situations such as fan-shaped, annular, and linear shapes.

Images