CN213021626U

CN213021626U - Universal measurement conversion circuit of photoelectric encoder based on DSP

Info

Publication number: CN213021626U
Application number: CN202021839563.7U
Authority: CN
Inventors: 田野; 曹继东; 李奎伟; 刘建民
Original assignee: Cama Luoyang Measurement and Control Equipments Co Ltd
Current assignee: Cama Luoyang Measurement and Control Equipments Co Ltd
Priority date: 2020-08-28
Filing date: 2020-08-28
Publication date: 2021-04-20
Anticipated expiration: 2030-08-28

Abstract

The utility model provides a general measurement converting circuit of photoelectric encoder based on DSP, including the DSP treater, a power supply circuit for supplying power to the DSP treater, a communication circuit for realizing communication between DSP treater and host computer, an incremental encoder processing circuit for connecting an incremental encoder and an absolute encoder processing circuit for connecting an absolute encoder, the incremental encoder processing circuit includes a bus transceiver chip and a differential line receiver chip for connecting the incremental encoder, the DSP treater links to each other with the bus transceiver chip and the differential line receiver chip in turn, the absolute encoder processing circuit includes an SSI interface parallel port module, the absolute encoder is connected to the DSP treater through the SSI interface parallel port module, the utility model discloses the processing speed is fast, the precision is high, the data is accurate, the reliability is good, and can gather multiple encoders, therefore, the motor measuring device can be widely applied to motor measuring equipment and has certain universality and market value.

Description

Universal measurement conversion circuit of photoelectric encoder based on DSP

Technical Field

The utility model belongs to the technical field of photoelectric encoder auxiliary measuring equipment, concretely relates to photoelectric encoder is general to be measured conversion circuit based on DSP.

Background

A photoelectric encoder is a sensor which converts motor motion parameters into pulse or digital quantity through photoelectric conversion, and is widely applied to the field of motor control and measurement feedback systems. Photoelectric encoders are classified into incremental encoders and absolute encoders according to their operating principles. The incremental encoder converts displacement into periodic electric signals, converts the electric signals into counting pulses, expresses the magnitude of the displacement by the number of the pulses, and generally has A, B, Z three-phase pulse output. The absolute encoder corresponds to a determined digital code at each position, the indication value of the absolute encoder is only related to the starting position and the ending position of measurement, two signal output modes of serial output or bus output are provided, and the serial output of the absolute encoder produced by Germany is most commonly synchronous serial output.

The existing output acquisition methods of various encoders are usually acquisition circuits based on a microcontroller, such as an incremental encoder acquisition circuit based on a single chip microcomputer and an absolute encoder acquisition circuit based on a DSP.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a can carry out the general measuring circuit who gathers to multiple encoder for accomplish the real-time measurement of motor position, speed, angle isoparametric.

In order to achieve the above purpose, the utility model adopts the technical scheme that: a universal measurement conversion circuit of a photoelectric encoder based on DSP comprises a DSP processor and a measurement conversion circuit,

the power supply circuit is used for supplying power to the DSP processor;

the communication circuit is respectively connected with the DSP and the upper computer and is used for realizing the communication between the DSP and the upper computer;

the input end of the incremental encoder processing circuit is connected with the incremental encoder, the output end of the incremental encoder processing circuit is directly connected to the DSP processor, and an enhanced orthogonal coding pulse module matched with the incremental encoder is arranged in the DSP processor;

and the input end of the absolute type encoder processing circuit is used for being connected with the absolute type encoder, and the output end of the absolute type encoder processing circuit is directly connected to the DSP processor.

Furthermore, the power supply circuit comprises a motor driver, an isolated direct current-direct current converter and a linear voltage stabilizer which are connected in sequence, and two output ends of the linear voltage stabilizer are respectively connected to the inner core and the IO port of the DSP processor.

Further, the communication circuit includes, but is not limited to, an ethernet communication circuit and an RS422 communication circuit.

Furthermore, the Ethernet communication circuit comprises a serial port-to-Ethernet module, the input end of the serial port-to-Ethernet module is connected to the peripheral pins of the DSP processor, and the output end of the serial port-to-Ethernet module is connected to the network port of the upper computer through a network cable.

Further, the RS422 communication circuit comprises a serial port transceiver chip, the input end of the serial port transceiver chip is connected to the peripheral pins of the DSP processor, and the output end of the serial port transceiver chip is connected to the serial port of the upper computer through a communication line.

Furthermore, the incremental encoder processing circuit comprises a bus transceiver chip and a differential line receiver chip for connecting the incremental encoder, and the DSP processor is connected with the bus transceiver chip and the differential line receiver chip in sequence.

Furthermore, a filter circuit is arranged between the incremental encoder processing circuit and the incremental encoder.

Furthermore, the absolute encoder processing circuit comprises an SSI interface parallel port module, and the absolute encoder is connected to the DSP processor through the SSI interface parallel port module.

Furthermore, a plurality of functional modules are integrated inside the SSI interface parallel port module, and the plurality of functional modules are connected to the DSP processor.

Further, the plurality of functional modules include, but are not limited to, an SSI synchronous clock generator module, a pulse counter module, a data serial-to-parallel conversion module, an interface control logic module, an output control module, and a transceiver driver module.

Compared with the prior art, the beneficial effects of the utility model are that: the utility model discloses the processing speed is fast, the precision is high, data are accurate, good reliability, and can gather multiple encoder, consequently can the wide application in motor measuring equipment, has certain commonality and market value.

Drawings

Fig. 1 is a schematic block diagram of a general measurement conversion circuit of a photoelectric encoder based on a DSP of the present invention;

fig. 2 is a circuit diagram of the power supply circuit of the present invention;

fig. 3 is a schematic diagram of the connection relationship between the DSP processor, the ethernet communication circuit and the upper computer network port;

FIG. 4 is a schematic diagram of the connection relationship between the DSP processor, the RS422 communication circuit and the serial port of the upper computer;

FIG. 5 is a schematic diagram of the connection relationship between the DSP processor and the incremental encoder according to the present invention;

fig. 6 is a schematic diagram of the connection relationship between the DSP processor and the absolute encoder according to the present invention.

Detailed Description

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the following will combine the drawings in the present invention to clearly and completely describe the technical solution in the embodiments of the present invention, and obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments, based on the embodiments in the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1, the utility model discloses mainly include microcontroller circuit, power supply circuit, communication circuit, incremental encoder processing circuit, absolute encoder processing circuit.

Wherein, the microcontroller circuit uses TMS320F28335 Digital Signal Processor (DSP) of TI company as the control core of the system, the DSP processor is a microprocessor which is specially provided by TI company and is specially used for the fields of motion control and motor control, and the detailed parameters and the reference circuit can be obtained by inquiring an official manual and are not detailed here.

As shown in fig. 2, the Power circuit includes a motor driver +24V, an isolated dc-dc converter and a linear regulator, which are connected in sequence, and two output terminals of the linear regulator are connected to an inner core and an IO port of the DSP processor, in this embodiment, the isolated dc-dc converter adopts an isolated dc-dc converter TEN8-2411 of Traco Power company, the linear regulator adopts a linear regulator TPS767D301PWP of TI company, the isolated dc-dc converter supplies Power with +5V, and an EMI input filter is built in the TEN8-2411 module, so that input and output voltages can be effectively isolated, and the Power circuit is suitable for being used in a strong interference environment of a motor system. The TEN8-2411 module is connected to the TI corporation linear regulator TPS767D301 PWP. Under the +5V working voltage, the chip TPS767D301PWP stably outputs +3.3V and +1.9V for the core and the IO port of the DSP processor.

The utility model provides a communication circuit supports two kinds of communication circuit of ethernet and RS422, can satisfy different user demands. The Ethernet communication circuit is realized by a W5500S2E-S1 serial port-to-Ethernet module of WIZnet company. The W5500S2E-S1 supports three working modes of TCP Server, TCP Client and UDP, and the maximum serial port baud rate can reach 1.152 Mbps. The hardware connection principle diagram of the DSP processor TMS320F28335 and the upper computer network port is shown in fig. 3. And a UART-B peripheral pin of the DSP processor is connected with a corresponding pin of the W5500S2E-S1 module, and the W5500S2E-S1 module is connected with a network port of the upper computer through a network cable. The DSP processor and the upper computer realize Ethernet communication through the W5500S2E-S1 module.

Compared with RS232, RS422 has advantages of anti-interference capability and communication distance, and is suitable for strong-current working environment of the motor. A schematic diagram of hardware connection between the DSP processor TMS320F28335 and an upper computer serial port is shown in fig. 4. The UART-A peripheral pins of the DSP processor are connected with corresponding pins of a serial port transceiver chip MAX3162EAI, and the chip MAX3162EAI is connected with a serial port of an upper computer.

The utility model provides an incremental encoder processing circuit includes bus transceiver chip and the differential circuit receiver chip that is used for connecting incremental encoder, and the DSP treater links to each other with bus transceiver chip and differential circuit receiver chip in proper order.

The DSP processor TMS320F28335 is internally integrated with an enhanced orthogonal coded pulse module (eQEP), and the eQEP is matched with an incremental photoelectric encoder for use, so that a perfect solution for high-precision and quick-response measurement of the motor can be provided. The input signals of the eQEP module comprise two orthogonal coding pulses A and B, a Z index pulse and an S selection input signal, and the selection signal can be connected to a position sensor or a limit switch to indicate the motor to rotate to a specified position. The hardware connection schematic between the DSP processor TMS320F28335 and the incremental encoder is shown in fig. 5.

The utility model discloses the electrical interface that supports incremental encoder is 5VTTL level signal, if measure the encoder of other electrical interfaces, can add corresponding converting circuit, converts 5VTTL level signal into. The A +/A-, B +/B-and Z +/Z-three pairs of differential signals of the incremental encoder are filtered and converted into single-ended signals A, B and Z through a differential line receiver chip AM26LS32 ACN. A. B and Z are 5VTTL level signals, are converted into LVTTL level signals through a bus transceiver chip SN74LVC245ADW, and enter eQEP1 peripheral pins EQEP1A (GPIO 20), EQEP1B (GPIO 21) and EQEP1I (GPIO 23) of a DSP processor TMS320F 28335.

The utility model provides an absolute formula encoder processing circuit includes that SSI interface changes and mouthful module, and absolute formula encoder changes and mouthful module is connected to the DSP treater through SSI interface.

The SSI208P module can automatically convert SSI data into 8-bit parallel data, and integrates the SSI synchronous clock generator, the pulse counter, the serial-parallel conversion of data, the interface control logic, the output control, and the transceiver driver (TTL and RS422 level conversion). The SSI208P module supports 3.3V power supply, the working current is less than 100mA, the communication rate can be configured to 2MHz, 8-bit data bus, 8-to-32-bit encoder can be considered, and 422 differential drive is built in.

The hardware connection schematic diagram of the DSP processor TMS320F28335 and the SSI208P module is shown in fig. 6. The general IO pin GPIO62 and GPIO63 of the DSP processor configure module synchronous clock frequency, GPIO64 switches module Gray code original code output or conversion BCD code output, GPIO65 and GPIO66 control module address bits, GPIO67 control module chip selection signals, GPIO68 inquires module end state, GPIO69 control module start signals, and parallel data converted by the GPIO 72-GPIO 79 acquisition module are acquired. If other microprocessors are used, the hardware circuitry may be analogized.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A universal measurement conversion circuit of a photoelectric encoder based on DSP comprises a DSP processor and is characterized by also comprising,

the power supply circuit is used for supplying power to the DSP processor;

2. The universal measurement conversion circuit for the DSP-based photoelectric encoder according to claim 1, wherein the power supply circuit comprises a motor driver, an isolated DC-DC converter and a linear regulator, which are connected in sequence, and two output ends of the linear regulator are respectively connected to an inner core and an IO port of the DSP processor.

3. The universal measurement conversion circuit for DSP-based optical-electrical encoder according to claim 1, wherein the communication circuit includes but is not limited to Ethernet communication circuit and RS422 communication circuit.

4. The universal measurement and conversion circuit for the DSP-based photoelectric encoder according to claim 3, wherein the Ethernet communication circuit comprises a serial-to-Ethernet module, an input end of the serial-to-Ethernet module is connected to a peripheral pin of the DSP processor, and an output end of the serial-to-Ethernet module is connected to an upper computer network port through a network cable.

5. The DSP-based universal measurement and conversion circuit for photoelectric encoders according to claim 3, wherein the RS422 communication circuit includes a serial transceiver chip, an input end of the serial transceiver chip is connected to a peripheral pin of the DSP processor, and an output end of the serial transceiver chip is connected to a serial port of an upper computer through a communication line.

6. The universal measurement conversion circuit for the DSP-based photoelectric encoder according to claim 1, wherein the incremental encoder processing circuit comprises a bus transceiver chip and a differential line receiver chip for connecting the incremental encoder, and the DSP processor is connected with the bus transceiver chip and the differential line receiver chip in turn.

7. The DSP-based photoelectric encoder general measurement conversion circuit according to claim 6, wherein a filter circuit is further disposed between the incremental encoder processing circuit and the incremental encoder.

8. The universal measurement conversion circuit for photoelectric encoders based on DSP as claimed in claim 1, wherein the absolute encoder processing circuit includes an SSI interface parallel interface module, and the absolute encoder is connected to the DSP processor through the SSI interface parallel interface module.

9. The universal measurement and conversion circuit for DSP-based optical-electrical encoders as claimed in claim 8, wherein a plurality of functional modules are integrated in the SSI port module, and the plurality of functional modules are commonly connected to the DSP processor.

10. The universal measurement converting circuit for photoelectric encoder based on DSP as claimed in claim 9, wherein the plurality of functional modules include but are not limited to SSI synchronous clock generator module, pulse counter module, data serial-to-parallel converting module, interface control logic module, output control module and transceiver driver module.