CN112600465A

CN112600465A - Multi-motor control circuit of thermal infrared imager

Info

Publication number: CN112600465A
Application number: CN202011434388.8A
Authority: CN
Inventors: 刘梁然; 刘纪洲; 青鸿阅; 许静
Original assignee: CETC 11 Research Institute
Current assignee: CETC 11 Research Institute
Priority date: 2020-12-10
Filing date: 2020-12-10
Publication date: 2021-04-02

Abstract

The invention discloses a multi-motor control circuit of a thermal infrared imager, which is applied to a multi-type thermal infrared imager, can complete the control of each motor of the thermal infrared imager, is matched with a motor control software program, and is matched and controlled with a related motor, a mechanical structure, a photoelectric switch and the like in a coordinated manner, can complete the multi-motor coordinated control with the time precision reaching 0.01 microsecond level and the position precision reaching 0.01 millimeter level, has various functions, adopts a system motor interface for subsequent update and maintenance, and has important significance for the research of a continuous zoom system and the motor control.

Description

Multi-motor control circuit of thermal infrared imager

Technical Field

The invention relates to the technical field of infrared detection, in particular to a thermal infrared imager multi-motor control circuit.

Background

With the development of infrared imaging technology in recent years, infrared zoom systems are widely used in the fields of monitoring, infrared foresight, target identification and the like. Compared with the traditional zoom system, the continuous zoom system can realize the conversion between the searching field and the tracking field without mutation, can keep the position of an image plane stable in the field conversion process, and can better realize the functions of fast and accurate tracking, target measurement and the like.

In the field of thermal infrared imagers, a hardware circuit takes an imaging circuit with a PPGA (pentatricopeptide genetic algorithm) as a processor as a core, motor control generally takes an ARM (advanced RISC machine) and an MCU (microprogrammed control unit) as processing cores, and the types of the processors need to be unified so as to reduce the development types of software and hardware and save development resources. Meanwhile, the circuit needs to be realized by cooperation of multiple motors for realizing continuous zooming, the types of motors in the thermal infrared imager are divided into a focusing motor and a view field motor according to the functions of the motors, the focusing function is realized by a stepping motor generally, the view field switching function is realized by a direct current motor, the number and the positions of the stepping motor and the direct current motor need to be designed according to the requirements of the thermal infrared imager, and therefore how to simultaneously meet the requirement that a driving control circuit applying multiple motors is an indispensable part of the thermal infrared imager.

Disclosure of Invention

The invention provides a multi-motor control circuit of a thermal infrared imager, which aims to solve the problem that the existing drive control circuit cannot be compatible with various motors at the same time.

The invention provides a thermal infrared imager multi-motor control circuit, comprising: the system comprises a field-editable logic gate array FPGA, an imaging circuit, a motor control module and a temperature sensor, wherein the imaging circuit, the motor control module and the temperature sensor are respectively connected with the FPGA;

the imaging circuit is connected with the FPGA through a serial port communication circuit, the FPGA receives a control command of the imaging circuit through the serial port communication circuit, and state information received by the FPGA is fed back to the imaging circuit in real time through the serial port communication circuit, so that the imaging circuit controls a corresponding motor to finish focusing and field of view switching through the FPGA according to the state information, and the state information comprises state information of the motor and temperature information of the temperature sensor;

the FPGA controls the work of the corresponding motor through the motor control module and receives encoder information of the motor;

and the FPGA receives the temperature information of the temperature sensor and controls a motor control module according to the temperature information and the encoder information so as to adjust the working state of the corresponding motor.

Optionally, the control circuit further comprises: a plurality of photoelectric switches disposed on the motor assembly;

the photoelectric switch monitors position information of a motor component of the motor and feeds the monitored position information back to the FPGA so that the FPGA controls the motor corresponding to the photoelectric switch to stop running or rotate reversely;

the motor comprises a direct current motor and an alternating current motor.

Optionally, the number of the motor control modules is three, and each motor control module is connected with the FPGA through a motor switching small plate.

Optionally, three of the motor control modules are arranged side by side on the motor control module.

Optionally, the motor adapter platelet is in the form of a double row inline detachable connector.

Optionally, the number of the two rows of pins of the motor adapter platelet is different, so as to prevent reverse insertion.

Optionally, according to the functional requirements, the motor interface is divided into three areas of a motor drive, an external interface and a universal motor, and the cable is standardized by adopting regional routing at preset intervals.

Optionally, the FPGA is provided with: the system comprises a CPU, a metronome and a plurality of motor control modules, wherein the motor control modules correspond to motors one to one;

the motor control modules respectively work in parallel under the control of the CPU and the synchronization of the metronome.

Optionally, the FPGA is further configured to receive the imaging circuit control signal to perform continuous zooming, field positioning, continuous zooming curve mode switching, temperature compensation and curve correction, and control the motor to perform electrical reset and zero calibration, fault detection and exception handling.

The invention has the following beneficial effects:

the motor control circuit is applied to a multi-type thermal infrared imager, can complete the control of each motor of the thermal imager, is matched with a motor control software program to be cooperatively matched and controlled with a related motor, a mechanical structure, a photoelectric switch and the like, can complete the multi-motor cooperative control with the time precision reaching 0.01 microsecond level and the position precision reaching 0.01 millimeter level, has various functions, adopts a system motor interface for subsequent updating and maintenance, and has important significance for the research of a continuous zoom system and the motor control.

The foregoing description is only an overview of the technical solutions of the present invention, and the embodiments of the present invention are described below in order to make the technical means of the present invention more clearly understood and to make the above and other objects, features, and advantages of the present invention more clearly understandable.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1 is a diagram of a hardware structure of a control circuit according to an embodiment of the present invention;

fig. 2 is a schematic structural diagram of a multi-motor circuit driving module according to an embodiment of the present invention;

FIG. 3 is a diagram of a modular discrete control-type software architecture provided by an embodiment of the present invention;

FIG. 4 is a graph illustrating a target position and an actual position recorded by a conventional control circuit;

FIG. 5 is a diagram illustrating a relationship between a target position and an actual position recorded by a control circuit according to an embodiment of the present invention;

fig. 6 is a schematic block diagram of a motor control circuit according to an embodiment of the present invention.

Detailed Description

In an existing thermal infrared imager, a hardware circuit takes a PPGA (patterned passive array) as an imaging circuit of a processor as a core, motor control generally takes an ARM (advanced RISC machine) and an MCU (microprogrammed control unit) as processing cores, and the types of the processors need to be unified so as to reduce development types of software and hardware and save development resources. Meanwhile, in order to realize continuous zooming, multiple motors are required to cooperate, and a special motor driving circuit is required to be designed. In addition, the types of motors in the thermal infrared imager are divided into a focusing motor and a field-of-view motor according to the functions of the motors, the focusing function is generally realized by a stepping motor, the field-of-view switching function is realized by a direct current motor, and the number and the positions of the stepping motor and the direct current motor need to be designed according to the requirements of the thermal infrared imager, so that the requirement that a driving control circuit applying various motors is an indispensable part of the thermal infrared imager is met.

The method aims at the following problems of motor control in the existing thermal infrared imager:

1. the motor control circuit adopts ARM and MCU as processors, and is different from the infrared imaging circuit processing circuit in software and hardware architecture, design idea and use scheme, so that additional design cost is brought;

2. under the great trend of home-made development of military weapon development components, home-made integrated circuits, ARM and MCU processor chips are not available in China as mature military-grade products, and need to be designed in a unified way, so that the types of core processors are reduced;

3. aiming at the motor control requirements of various thermal infrared imagers, a motor control circuit needs to meet the drive control of two different motors on one hand and meet the compatible design of at most three motor controls on the other hand, and the existing circuit cannot be compatible with the functions simultaneously;

4. the existing motor control software architecture also has the following problems: the high-frequency interruption response capability can not meet the application requirement due to the congenital reasons of the ARM processor and the MCU processor; the electromechanical software control module is not flexible enough, has poor adaptability to different continuous zooming optical systems, and needs to change programs in large quantity.

In view of the above problems, an embodiment of the present invention provides a thermal infrared imager multi-motor control circuit, as shown in fig. 1, which includes a field-editable logic gate array FPGA, an imaging circuit, a motor control module, and a temperature sensor, wherein the imaging circuit, the motor control module, and the temperature sensor are all connected to the FPGA respectively;

Specifically, the motor control circuit of the embodiment of the invention takes the FPGA as a control core, and three or more motor control modules can be simultaneously controlled by feeding back position information through the photoelectric switch or the limit switch.

The motor control circuit in the embodiment of the invention is connected with the imaging circuit through serial port communication, receives related control commands and feeds back the state; the FPGA is connected with the motor control module, controls the motor to work, receives encoder information, receives signals of a photoelectric switch, a temperature sensor and the like, and monitors various states in real time.

In specific implementation, the motor control circuit provided by the embodiment of the invention can meet various control schemes of a three-step motor, a double-step motor, a single direct current single machine, a three-direct current motor, a double-direct current motor, a single direct current motor and the like. According to the embodiment of the invention, two motor driving chips are selected as a two-way direct current motor driving chip and a stepping motor driving chip respectively by combining various index requirements such as a motor driving mode, power supply voltage, driving current and the like. In order to realize various motor linkage control schemes, the two types of motor control modules can be flexibly replaced according to different requirements, and the compatible motor drive circuit module is shown in fig. 2.

Specifically, the A, B, C part in the embodiment of the invention is a motor switching small plate part, the switching small plates in the embodiment of the invention all adopt a double-row straight-line detachable connector form, and the reverse insertion can be prevented due to the fact that the number of two rows of inserting pins is different.

In the embodiment of the invention, the motor control circuit needs to drive a motor and also needs to receive signals such as a motor encoder, the position of a motor assembly, the ambient temperature and the like, more connectors are needed for hardware cable connection, and if a conventional interconnection mode is adopted, the number of the connectors is more, the wiring is complex, the occupied circuit board space is large and the like.

The FPGA is provided with: the system comprises a CPU, a metronome and a plurality of motor control modules, wherein the motor control modules correspond to motors one to one; the motor control modules respectively work in parallel under the control of the CPU and the synchronization of the metronome.

Furthermore, in the embodiment of the invention, the thermal infrared imager motor control software is mainly controlled and completed through an FPGA program, and in order to ensure the flexibility of a motor control algorithm and the accuracy and precision of a control waveform, the functional module is realized by a soft core CPU and an upper layer C language. The bottom layer driving is realized by a beat synchronization core and a motor control core VHDL language, the beat synchronization core and the motor control core VHDL language are packaged into a self-defined IP core, a soft core CPU is called through an Avalon bus, a plurality of examples can be configured according to the actual number of motors, the examples respectively work in parallel under the control of the CPU and the beat synchronization, and a software architecture diagram is shown in FIG. 3.

The motor control self-defined IP can be configured with a plurality of instances according to the number of the motors, and the instances respectively work in parallel under the control of the CPU and the synchronization of the metronome. The bus interface is responsible for communication between the user-defined IP and the embedded soft core, and the function control, data configuration and feedback of the user-defined IP are completed. The universal interface of the motor and external parametric adjustment are added to the upper-layer control, so that the electromechanical control module is favorably suitable for different optical systems and optical parameters.

In order to adapt to multifunctional curve superposition control (such as zooming, focusing, object distance compensation and temperature compensation, which are controlled on the same mirror according to curve superposition), an external interface is added in an electromechanical control module, and the multi-element curve can be subjected to linear or nonlinear correction along with the change of environment, object distance and other application conditions. The method comprises the correction of increasing temperature coefficient, the correction of focusing optical zero position, the correction of idle return of a focusing assembly and the like, and is better applied to the application functions of a continuous zooming module or a focusing module (such as the functions of object distance compensation, object distance setting and the like).

In the control of a direct current motor (especially in a continuous zooming system of a cam-type multi-element direct current motor), the original concept of semi-closed-loop control of the direct current motor is overturned, a brand-new double-closed-loop PID control algorithm of a position loop and a speed loop is established, and the position control precision of the direct current motor is greatly improved. The continuous zooming optical system of the cam type multi-component direct current motor multi-curve change superposition is realized for the first time.

Sampling is carried out at a time interval of 1ms, the relation between the target position and the actual position is recorded, the first 250ms from the start to the stabilization is selected, and a curve relation pair before and after the algorithm is upgraded is obtained, such as shown in fig. 4 and 5. As can be seen from fig. 4 and 5, the motor always follows the change of the target position from start to stop, and the following performance is good.

In specific implementation, the embodiment of the invention completes the following functions through FPGA program control: the method comprises the steps of a continuous zooming process, a visual field positioning process, continuous zooming curve mode switching, temperature compensation and curve correction, motor power-on reset and zero calibration, fault detection, exception handling and the like.

As shown in fig. 6, which is a schematic block diagram of the entire motor control circuit according to the embodiment of the present invention, as can be seen from fig. 6, the circuit first filters the power, one path directly supplies power to the VM power of the motor, and the other path performs voltage conversion through the DCDC chips LMZ14203 and LM73606 to generate a 5V power and a 5.5V power, respectively, where the 5V power supplies power to the photoelectric switch, the temperature monitoring chip, the fan control chip, and the like. The 5.5V power supply generates the FPGA power supply through a plurality of LDOs: 1.1V, 2.5V, 3.3V and the like, and 3.3V is also a power supply of the FPGA peripheral configuration chip. The FPGA controls the motor through three motor control modules and receives feedback information such as the environment temperature of the encoder. The circuit is matched with an FPGA program to complete a series of motor control functions.

The motor control circuit is an important component of the thermal imager, a processor FPGA which is the same as an imaging circuit of the thermal imager is adopted, a control circuit which is compatible with multiple motors is designed, and functions of focusing, field switching, motor power-on reset and zero calibration, temperature compensation and curve correction, fault detection and the like of the thermal imager are completed by matching with related software programs. The method is applied to a multi-type thermal infrared imager and is used for connecting related circuits and other components in the thermal infrared imager.

Generally, the motor control circuit provided by the embodiment of the invention is applied to a multi-type thermal infrared imager, can complete the control of each motor of the thermal imager, is matched with a motor control software program to be cooperatively matched and controlled with a related motor, a mechanical structure, a photoelectric switch and the like, can complete the cooperative control of a plurality of motors with the time precision reaching 0.01 microsecond level and the position precision reaching 0.01 millimeter level, has various functions, adopts a system motor interface for subsequent updating and maintenance, and has important significance for the research of a continuous zoom system and motor control.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, and the scope of the invention should not be limited to the embodiments described above.

Claims

1. A thermal infrared imager multi-motor control circuit is characterized by comprising: the system comprises a field-editable logic gate array FPGA, an imaging circuit, a motor control module and a temperature sensor, wherein the imaging circuit, the motor control module and the temperature sensor are respectively connected with the FPGA;

2. The thermography multi-motor control circuit of claim 1, further comprising: a plurality of photoelectric switches disposed on the motor assembly;

the motor comprises a direct current motor and an alternating current motor.

3. The thermography multi-motor control circuit of claim 1,

the number of the motor control modules is three, and each motor control module is connected with the FPGA through a motor switching small plate.

4. The thermography multi-motor control circuit of claim 3,

and the three motor control modules are arranged on the motor control modules side by side.

5. The thermography multi-motor control circuit of claim 3,

the motor switching platelet adopts the double-row straight-line detachable connector form.

6. The thermography multi-motor control circuit of claim 5,

two rows of contact pins of the motor switching small plate are different in number so as to prevent reverse insertion.

7. The thermography multi-motor control circuit of claim 1,

according to the functional requirements, the motor interface is divided into three areas of a motor drive, an external interface and a universal motor, and the wires are wired in a regional mode at preset intervals to standardize the cables.

And connecting the regions by adopting a preset interval to standardize cables.

8. The thermography multi-motor control circuit of claim 7,

the preset distance is 1.27 mm.

9. The thermography multi-motor control circuit of claim 1,

the FPGA is provided with: the system comprises a CPU, a metronome and a plurality of motor control modules, wherein the motor control modules correspond to motors one to one;

10. The thermography multi-motor control circuit of claim 1,

the FPGA is also used for receiving the imaging circuit control signal to perform continuous zooming, field positioning, continuous zooming curve mode switching, temperature compensation and curve correction, and controlling the motor to perform electric reset and zero calibration, fault detection and exception handling.