CN112649019A - Small-size high-precision resolver angle resolving circuit - Google Patents

Abstract

The invention discloses a small-size high-precision resolver angle calculating circuit, and particularly relates to an angle calculating circuit suitable for an angle sensitive element resolver of a micro indexing mechanism of inertial navigation online self-calibration equipment. The resolving circuit comprises a second-order low-pass filter, a digital resolver, an FPGA logic module and a DSP digital signal processing module. The second-order low-pass filter is connected with the SIN phase and COS phase analog signals output by the rotary transformer and the digital resolver; the digital resolver is connected with the second-order low-pass filter and the FPGA logic module; the FPGA logic module is connected with the digital solver and the DSP digital signal processing module; and the DSP digital signal processing module is connected with the FPGA logic module to realize the conversion from the analog signal output by the rotary transformer to the corner. The circuit has the characteristics of small volume and high precision, and simultaneously meets the dual requirements of the indexing mechanism of the inertial navigation self-calibration equipment on volume and precision.

Description

Small-size high-precision resolver angle resolving circuit

Technical Field

The invention relates to a small-size high-precision resolver angle calculating circuit, in particular to an angle calculating and measuring circuit suitable for an angle sensitive element resolver of a micro indexing mechanism of inertial navigation online self-calibration equipment.

Background

The resolver is an angle sensitive element, and is commonly applied to a rotary shaft servo control system as an angle feedback element together with a circular grating, an angle encoder and a circular induction synchronizer. The rotary transformer has small volume, convenient installation, high adaptability to severe environment, high and low temperature resistance and strong shock vibration resistance; the circular grating and the angle encoder have high precision and large volume, but have poor adaptability to high and low temperature, shock vibration resistance and other environments, and are generally used in laboratories or industrial control occasions; the circular induction synchronizer has high adaptability to severe environment, but the installation process is complex, the clearance between the rotor and the stator needs to be strictly controlled, the time drift is difficult to control, and the precision of the circular induction synchronizer generally changes along with the time.

The micro indexing mechanism is an inertial navigation (gyro) online self-calibration device, the conventional inertial navigation calibration device is a rotary table, and generally comprises a single-axis rotary table, a double-axis rotary table, a three-axis rotary table and a five-axis rotary table, the size and the weight of the rotary table are large, the rotary table is used for providing standard attitude, position, rate information and the like for the gyro in a laboratory, the gyro is generally arranged on a table top in the rotary table, so that the calibration of the gyro is realized, and the gyro is detached and then is arranged in a missile again after the calibration is.

In recent years, with the increasing requirements of various countries on the real-time performance, dynamic response and maneuverability of military weapon operation, particularly for guided missiles, the gyro is a navigation positioning and orienting device of the guided missiles, the traditional mode of calibrating the gyro by using a rotary table in a laboratory and then installing the gyro on the guided missiles cannot meet the requirements of the guided missiles on the strong real-time performance, the high dynamic response and the high maneuverability operation performance, so that the guided missiles are required to perform online self-calibration and correction on the gyro at any time in the operation process, and the micro indexing mechanism can well meet the requirements. The miniature indexing mechanism is a reduced version of a conventional turntable, the conventional turntable has the advantages of volume, length, width, height and three directions of about 1-5 meters, weight of hundreds of Kg to several tons, and high precision. The micro indexing mechanism is arranged in the missile and belongs to one of missile components, the gyroscope is arranged on an inner shaft table surface of the micro indexing mechanism, and the missile can perform online self-calibration on an inertial navigation gyroscope of the missile at any time in the process of operation and flight, so that the operational maneuverability and dynamic response of the missile are greatly improved. The diameter of the bullet directly determines the size of the internal micro indexing mechanism, and the external diameter of the micro indexing mechanism cannot exceed the internal diameter of the bullet, so that higher requirements are provided for the volume and weight of each mechanism, module and circuit board in the micro indexing mechanism.

Because the rotary transformer has the advantages, the rotary transformer is very suitable for the requirements of wide temperature and strong shock vibration resistance in the missile flying process, and has small volume and convenient installation, the rotary transformer adopted by the indexing mechanism as an angle sensitive and feedback element is the most ideal choice. However, at present, the angle calculation of the rotary transformer in China generally adopts some ready-made packaged rotary transformer digital converter (RDC) modules of military scientific research institute, the highest precision can reach 3', but the size is large (about 50mm multiplied by 25mm), one RDC module can only calculate a single rotary transformer of a certain shaft, an extra large-size excitation module is also needed, other circuit modules of a control system are added, the size of the whole circuit is large, the thickness is difficult to control, and the rotary transformer angle calculation method is difficult to apply to occasions with strict requirements on the size, such as a micro indexing mechanism.

The resolver angle calculating circuit provided by the invention adopts the existing resolver/synchro rotation angle calculating chip AD2S1210 with complete functions, so that the resolver angle calculating circuit in the indexing mechanism can be made very small, each resolver only needs two AD2S1210, and other measurement and control circuits in the system are added, a typical double-shaft micro indexing mechanism is taken as an example, the whole circuit board in the resolver can be 100mm multiplied by 80mm multiplied by 5mm (length multiplied by width multiplied by height), the angle calculating precision can reach 4 ", and the dual requirements of the micro indexing mechanism on the circuit board volume and the system precision can be well met.

Disclosure of Invention

The invention aims to solve the technical problem of a small-volume high-precision resolver angle calculating circuit, and explores a high-precision resolver angle calculating circuit applied to the interior of a micro indexing mechanism with strictly limited volume space.

The technical scheme adopted by the invention for solving the technical problems is as follows: the circuit for resolving the angle of the rotary transformer by adopting the small AD2S1210 chip comprises a second-order low-pass filter, a digital resolver, an FPGA logic module and a DSP digital signal processing module. The second-order low-pass filter is connected with SIN phase and COS phase analog signals output by the rotary transformer and the digital resolver; the digital resolver is connected with the second-order low-pass filter and the FPGA logic module; the FPGA logic module is connected with the digital solver and the DSP digital signal processing module; and the DSP digital signal processing module is connected with the FPGA logic module, so that the calculation and measurement from sine and cosine analog signals output from the coarse and fine channels of the rotary transformer to a corner are realized.

The invention has the beneficial effects that:

1. the whole resolving circuit board is small in size and is very suitable for angle resolving and measuring of a micro indexing mechanism of inertial navigation on-line self-calibration equipment with strictly limited volume space;

2. the precision is high, and the angle resolving precision can reach 4' at most;

3. can well meet the double requirements of the indexing mechanism on volume and precision.

Drawings

FIG. 1 is a schematic block diagram of the present resolver.

Fig. 2 is a schematic diagram of the structural composition and logic of a measurement and control board of the micro indexing mechanism (dual-axis) including a resolver circuit according to the present invention.

Detailed Description

As shown in fig. 2, the present embodiment includes a dual-axis micro-indexing mechanism, an upper computer (including application software of the present system), and an RS422/USB converter. The double-shaft micro indexing mechanism comprises a mechanical table body of the double-shaft indexing mechanism, two motors, two micro motor driving modules, two rotary transformers and a measurement and control circuit board (including a rotary transformer resolving circuit). The measurement and control circuit board comprises a second-order low-pass filter (4 paths), a digital resolver (4 paths) composed of AD2S1210, an FPGA logic module, a DSP digital signal processing module, an IO input/output module, a user interface module, a power supply module and the like. The IO input and output module mainly comprises a zero position signal, a limit signal, an overspeed signal and the like which are input by the indexing mechanism, and a motor enable signal, a motor driver control signal and the like which are output by the indexing mechanism.

Example (b):

each path of second-order low-pass filter filters SIN and COS phase analog signals output by a coarse channel and a fine channel of a rotary transformer, mainly filters high-frequency interference of a motor and a driver in a system, the filtered SIN and COS phase analog signals are input to an AD2S1210 chip of a digital resolver, the AD2S1210 chip completes conversion of the SIN and COS phase analog signals to 16-bit digital angle signals under the control of an FPGA logic module and outputs the 16-bit digital angle signals to the FPGA, the FPGA transmits the received 16-bit digital angle signals of the coarse channel and the fine channel corresponding to the SIN and the COS phase analog signals to a DSP digital signal processing module through an EMIF interface, the DSP digital signal processing module performs coupling operation on angles of the coarse channel and the fine channel through a certain algorithm to obtain a real-time angle value of the rotary transformer of a current axis and serves as a feedback signal for controlling the motor, the angle is input to a PID control algorithm, and control quantity is output to a motor micro-driving module after DA conversion, thereby controlling the motor to operate according to a predetermined target. The upper computer can receive the angle and other real-time data of the current micro indexing mechanism through the RS422/USB interface, and can also send instruction information such as enable, target position, speed and the like to the micro indexing mechanism, so that the controlled operation of the micro indexing mechanism is realized. The embodiment is successfully applied to an inertial navigation online self-calibration system in multi-type bombs in China.

The above description is only exemplary of the present invention, and all equivalent changes and modifications of the circuit structure, features and principles described in the present invention are included in the scope of the present invention.

Claims (2)

1. The utility model provides a circuit is solved to little volume high accuracy resolver angle which characterized in that: the resolving circuit comprises a second-order low-pass filter, a digital resolver, an FPGA logic module and a DSP digital signal processing module. The second-order low-pass filter is connected with SIN phase and COS phase analog signals output by the rotary transformer and the digital resolver; the digital resolver is connected with the second-order low-pass filter and the FPGA logic module; the FPGA logic module is connected with the digital solver and the DSP digital signal processing module; and the DSP digital signal processing module is connected with the FPGA logic module, so that the conversion from sine and cosine analog signals output from the coarse and fine channels of the rotary transformer to a corner is realized.

2. The digital resolver according to claim 1, wherein: the digital resolver mainly comprises a resolver/synchro digital resolving chip of Analog Devices company, the model number of which is AD2S1210, 48-pin TQFP packaging is adopted, and the volume of the resolver is 9mm multiplied by 1.4mm (length multiplied by width multiplied by height). The AD2S1210 can perform AD conversion on SIN phase and COS phase analog signals output by the rotary transformer under the control of the FPGA logic module and then perform conversion on digital angle quantity, the clock is provided by the FPGA and has the frequency of 8.192MHZ, the excitation signal is generated by programming the AD2S1210, and the mode selection A0 and A1 signals, the chip selection CS signal, the sampling signal SAMPLE, the read-write signal and the 16-bit parallel data line signal of the AD2S1210 are respectively connected with the IO pin of the FPGA.

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