CN115226296A

CN115226296A - Electronic system for compact rudder and steering engine

Info

Publication number: CN115226296A
Application number: CN202110422746.1A
Authority: CN
Inventors: 马一通; 魏厚震; 余东东; 李磊; 马俊
Original assignee: Beijing Machinery Equipment Research Institute
Current assignee: Beijing Machinery Equipment Research Institute
Priority date: 2021-04-16
Filing date: 2021-04-16
Publication date: 2022-10-21

Abstract

The invention relates to an electronic system for a compact rudder and a steering engine, comprising an integrally formed rigid-flex printed board; the rigid board area of the rigid-flex printed board comprises a control circuit bearing board, a driving circuit bearing board and a power circuit bearing board; the control circuit bearing plate is connected with the driving circuit bearing plate through a first flexible plate; the driving circuit bearing plate and the power circuit bearing plate are connected through a second flexible plate; the first flexible plate and the second flexible plate are bent, so that the mounting positions of the control circuit bearing plate and the driving circuit bearing plate are parallel, the mounting positions of the power circuit bearing plate and the driving circuit bearing plate are perpendicular, and the compact mounting of the rigid-flex printed board in the built-in space of the steering engine shell is realized. The invention adopts the planarization design of the rigid-flexible printed board, and the three-dimensional layout after bending replaces the connection of internal cables, so that the structure is more compact, the space occupation is small, and the manufacturability is more optimized; the personnel cost is saved, the quality is ensured, and the misoperation probability is reduced.

Description

Electronic system for compact rudder and steering engine

Technical Field

The invention relates to the technical field of steering engines, in particular to a compact electronic system for a steering engine and the steering engine.

Background

The physical layout of mechanical actuating mechanisms such as a motor, a speed reducer, a sensor, a lead screw and a shifting fork in the steering engine causes narrow and dispersed space of a circuit part. The traditional circuit board stacking mode has insufficient electromechanical combination degree, and leads to low space ratio. Due to the particularity of the mechanical structure and the absence of a dedicated circuit slot or circuit box, the connection between the circuit board and the motor sensor or the connection between the circuit board and the circuit board needs to be considered. The plug-in connector is installed in a relatively large size, and a plug-in operation space needs to be reserved. Especially in the design of electromechanical products with narrow space, how to reasonably utilize the limited space and not bring the difficulty of the production and installation of accessories become the key problem restricting the compactness of the products.

Disclosure of Invention

In view of the above analysis, the present invention aims to provide a compact electronic system for a rudder and a steering engine, so as to at least partially solve at least one of the above technical problems.

The technical scheme provided by the invention is as follows:

the invention discloses a compact electronic system for a rudder, which comprises an integrally formed rigid-flex printed board; the rigid board area of the rigid-flex printed board comprises a control circuit bearing board, a driving circuit bearing board and a power circuit bearing board;

the control circuit bearing plate and the driving circuit bearing plate are connected through a first flexible plate; the driving circuit bearing plate and the power circuit bearing plate are connected through a second flexible plate;

the first flexible plate and the second flexible plate are bent, so that the mounting positions of the control circuit bearing plate and the driving circuit bearing plate are parallel, the mounting positions of the power circuit bearing plate and the driving circuit bearing plate are perpendicular, and the steering engine shell is used for realizing compact mounting of the rigid-flexible printed board in the built-in space of the steering engine shell.

Furthermore, the control circuit bearing plate and the driving circuit bearing plate are both a one-piece rigid circuit board;

one end of the first flexible plate is connected with the edge of the control circuit bearing plate, and the other end of the first flexible plate is connected with the edge of the driving circuit bearing plate; after the first flexible board is bent inwards twice by 90 degrees, the control circuit bearing board is parallel to the driving circuit bearing board;

the power circuit bearing plate comprises four separated power circuit sub-plates with the same structure; the second flexible board comprises four L-shaped flexible circuit boards with the same structure;

one ends corresponding to the long edges of the four L-shaped flexible circuit boards are respectively connected with the edge of the drive circuit bearing plate, so that the four L-shaped flexible circuit boards are uniformly distributed on the periphery of the drive circuit bearing plate; one ends corresponding to the short edges of the four L-shaped flexible circuit boards are respectively connected with the edges of the four power circuit sub-boards;

one end corresponding to the long edge of each L-shaped flexible plate is bent 90 degrees towards the opposite direction of the position of the control circuit bearing plate, one end of the short edge is bent 90 degrees inwards, so that the four power circuit sub-plates are respectively vertical to the drive circuit bearing plate, and the spatial positions among the four power circuit sub-plates are in a cross shape.

Further, the device also comprises a mounting structure; the mounting structure comprises a base, four vertical mounting plates and a horizontal mounting plate;

the mounting surface of the base is perpendicular to the shell of the steering engine and parallel to the horizontal mounting plate; the four vertical mounting plates are rectangular metal plates with the same shape; the four vertical mounting plates are respectively arranged between the mounting surface of the base and the horizontal mounting plate and are vertical to the mounting surface of the horizontal mounting plate and the base; the spatial positions among the four vertical mounting plates are in a cross shape;

each rectangular metal plate is used for fixing a power circuit sub-board, is tightly contacted with the power elements on the power circuit sub-board and is used as a heat dissipation plate of the power elements;

the horizontal mounting plate is provided with three mounting holes with equal angles and three mounting columns with equal angles and equal lengths;

the mounting hole is used for mounting a driving circuit bearing plate; the mounting column is used for mounting a control circuit bearing plate.

Furthermore, the control circuit bearing plate is used for bearing an embedded control circuit, a sensor conditioning circuit, a communication circuit and a first power supply conversion circuit of the rudder electronic system;

the sensor conditioning circuit is used for conditioning signals collected by the sensor including temperature, angle, current and torque to obtain steering engine sensing signals;

the embedded control circuit is used for generating four paths of steering engine control logics including PWM (pulse width modulation) and DIR (direct) according to the steering engine sensing signals and external control signals by adopting a 'one-to-four' control program in the embedded control circuit, and respectively controlling the motion of four brushless motors of the steering engine;

the communication circuit is used for receiving an external control signal and sending a state signal of the steering engine to the outside;

the first power conversion circuit is used for converting externally input voltage and supplying power to the circuit unit on the control circuit bearing plate.

Further, the embedded control circuit comprises a processor STM32G474RET3 and corresponding peripheral circuits;

the sensor conditioning circuit is a constant-current type resistance-sensitive sensor signal conditioning circuit and is used for conditioning sensor signals acquired by a resistance type RTD temperature sensor, a strain gauge type torque sensor and a power resistance type bus current sensor;

the communication circuit comprises an RS422 and CAN double communication interfaces.

Further, the driving circuit bearing plate is used for bearing a brushless motor driving circuit, a current monitoring circuit and a second power supply conversion circuit of the rudder electronic system;

the brushless motor driving circuit generates three-phase driving voltage required by the rotation of four brushless motors of the steering engine according to collected Hall sensing information of a rotor of the brushless motor and four steering engine control logics output by the embedded control circuit;

the current monitoring circuit is used for monitoring the bus currents of the four brushless motors of the steering engine to obtain current information;

and the second power supply conversion circuit is used for converting the voltage input from the outside and supplying power to the circuit unit on the driving circuit bearing plate.

Further, the brushless motor driving circuit comprises four identical motor driving sub-circuits; each motor driving sub-circuit adopts a driving logic generation chip UCC2626, and generates three-phase driving voltage required by the rotation of the corresponding brushless motor according to the Hall sensing information of the rotor of the corresponding brushless motor and the PWM & DIR steering engine control logic output by the embedded control circuit;

the current monitoring circuit comprises four identical current monitoring sub-circuits; each current monitoring sub-circuit adopts an isolated sigma-delta modulator AD7403 to monitor the bus current of the corresponding brushless motor.

Furthermore, each power circuit sub-board is used for bearing a three-phase inverter power circuit, a temperature monitoring circuit and a bottom layer power supply circuit of a brushless motor of the rudder power electronic system;

the three-phase inverter power circuit adopts a drive tube and a power MOS tube packaged by DirectFET to carry out drive amplification and power amplification on the input three-phase drive voltage and outputs the three-phase drive voltage to a corresponding brushless motor;

the temperature monitoring circuit adopts a resistance RTD temperature sensor to monitor the heat dissipation and the temperature of the power device.

Further, the first flexible board and the second flexible board are also used as signal transmission channels between the rigid board areas;

the first flexible board and the second flexible board at least comprise three metal conductive layers, wherein the uppermost layer and the lowermost layer are metal conductive layers and are used for shielding external electromagnetic interference and avoiding signal distortion generated on the flexible boards by signal transmission; the metal conductive layer of the intermediate layer is used for establishing a signal transmission channel between the rigid plate areas.

The invention also discloses a steering engine which comprises the electronic system for the compact rudder.

The invention can realize at least one of the following beneficial effects:

the rigid-flex printed board adopts the planar design of the rigid-flex printed board, and the bent three-dimensional layout replaces the connection of internal cables, so that the structure is more compact, the space occupation ratio is small, and the manufacturability is more optimized;

due to the three-dimensional design of the rigid-flexible printed board, the assembly time is saved, the processes of electric fitting welding and field inspection are omitted, the specific gravity of the product quality is increased due to the design guarantee, and the process guarantee is weakened; the personnel cost is saved, the quality is ensured, and the misoperation probability is reduced.

The device is beneficial to mass production, high in efficiency and high in yield, ensures rapid design and rapid assembly, and provides powerful support for modernization of equipment.

Drawings

The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, wherein like reference numerals are used to designate like parts throughout.

Fig. 1 is an expanded front view of an electronic system for a compact rudder according to the present embodiment;

fig. 2 is a schematic reverse side view of the electronic system for a compact rudder according to the present embodiment;

fig. 3 is a schematic structural view of an electronic system mounting bracket for a compact rudder according to the present embodiment;

fig. 4 is an overall assembly diagram of the electronic system for a compact rudder according to the present embodiment.

Detailed Description

The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form a part hereof, and which together with the embodiments of the invention serve to explain the principles of the invention.

The embodiment discloses an electronic system for a compact rudder, which comprises an integrally formed rigid-flex printed board as shown in fig. 1 and 2; the rigid board area of the rigid-flex printed board comprises a control circuit bearing board, a driving circuit bearing board and a power circuit bearing board;

Specifically, the control circuit bearing plate and the driving circuit bearing plate are both a one-piece rigid circuit board;

the shape structures of the control circuit bearing plate and the driving circuit bearing plate can be matched with the shape structure of the built-in space of the shell of the steering engine. If the built-in space of the steering engine shell is cylindrical, the control circuit bearing plate and the driving circuit bearing plate are circular plates; in order to meet the optimal layout and wiring of the circuit board, the diameters of the control circuit bearing plate and the driving circuit bearing plate meet the maximum diameter meeting the installation tolerance with the built-in space of the steering engine shell.

One end of the first flexible plate is connected with the edge of the control circuit bearing plate, and the other end of the first flexible plate is connected with the edge of the driving circuit bearing plate; after bending for two times of 90 degrees inwards, the control circuit bearing plate is parallel to the driving circuit bearing plate;

the power circuit bearing plate comprises four discrete power circuit sub-plates with the same structure and rigidity; the second flexible board comprises four L-shaped flexible circuit boards with the same structure;

one ends corresponding to the long edges of the four L-shaped flexible circuit boards are respectively connected with the edge of the drive circuit bearing plate, so that the four L-shaped flexible circuit boards are uniformly distributed on the periphery of the drive circuit bearing plate; one ends corresponding to the short edges of the four L-shaped flexible circuit boards are respectively connected with the edges of the four power circuit sub-boards; the positions of the four L-shaped flexible circuit boards are distributed at intervals of 90 degrees circumferentially relative to the driving circuit bearing board.

One end corresponding to the long edge of each L-shaped flexible plate is bent 90 degrees towards the opposite direction of the position of the control circuit bearing plate, one end of the short edge is bent 90 degrees inwards, so that the four power circuit sub-boards are respectively vertical to the drive circuit bearing plate, and the spatial positions of the four power circuit sub-boards are crossed.

In order to ensure that the installation of the flexible board of the rigid-flex printed board which is bent into a three-dimensional layout does not influence the installation of the built-in space of the steering engine shell after the flexible board is bent, the edge of the control circuit bearing board connected with the first flexible board and the edge of the drive circuit bearing board connected with the first flexible board and the second flexible board respectively comprise an inner groove, and the depth of the inner groove is determined according to the condition that the bent edge does not exceed the depth of the groove when the first flexible board and the second flexible board are bent.

In order to ensure that the rigid-flex printed board which is bent into a three-dimensional layout is stably installed, the rigid-flex printed board also comprises an installation structure; as shown in fig. 3, the mounting structure includes a base, four vertical mounting plates and a horizontal mounting plate;

the mounting surface of the base is perpendicular to the shell of the steering engine and parallel to the horizontal mounting plate; the four vertical mounting plates are rectangular metal plates with the same shape; the four vertical mounting plates are respectively arranged between the mounting surface of the base and the horizontal mounting plate and are vertical to the mounting surface of the horizontal mounting plate and the base; the spatial positions of the four vertical mounting plates are in a cross shape; and the outer side corner of the vertical mounting plate, which is in contact with the mounting surface of the base, is provided with a mounting base, and the base is provided with a mounting hole for fixing the vertical mounting plate on the mounting surface of the base.

Each rectangular metal plate is provided with a mounting hole for mounting and fixing a power circuit sub-board; the rectangular metal plate is tightly contacted with the power element on the power circuit sub-board to be used as a heat radiation plate of the power element; preferably, the contact surface between the power element and the heat dissipation plate is coated with heat conductive silicone to increase heat conduction efficiency.

the mounting hole is used for mounting a driving circuit bearing plate; the mounting column is used for mounting a control circuit bearing plate; the length of the mounting post matches the length of the first flexible plate.

The compact rudder electronic system is integrally assembled as shown in fig. 4, and comprises a horizontal control circuit bearing plate, a horizontal driving circuit bearing plate and four vertical power circuit sub-boards from top to bottom in sequence; the brushless motor and the related equipment corresponding to each power circuit daughter board are assembled in four independent spaces defined by the mounting base, the power circuit daughter boards and the driving circuit bearing board, and the steering engine electronic system is compactly mounted. And the driving circuit bearing plate is arranged between the control circuit bearing plate and the four power circuit sub-plates, so that the driving circuit bearing plate plays an electromagnetic shielding role between the control circuit and the power circuit, and the interference of high-frequency electromagnetic signals in the working process of the power circuit on the control signals in the control circuit is prevented.

Preferably, the first flexible board and the second flexible board of the integrally molded rigid-flex printed board are used as a signal transmission channel between the rigid board regions besides being used as the connection of the rigid board regions;

the first flexible board and the second flexible board at least comprise three metal conductive layers, wherein the uppermost layer and the lowermost layer are metal conductive layers and are used for shielding external electromagnetic interference and avoiding signal distortion generated on the flexible boards by signal transmission; the metal conductive layer of the middle layer is used for establishing a signal transmission channel between the rigid plate areas.

The three-dimensional layout after bending of the rigid-flex printed board is used for replacing internal cable connection, so that the structure is more compact, the space occupation ratio is small, and the manufacturability is more optimized; due to the three-dimensional design of the rigid-flexible printed board, the assembly time is saved, the processes of electric fitting welding and field inspection are omitted, the specific gravity of the product quality is increased due to the design guarantee, and the process guarantee is weakened; the personnel cost is saved, the quality is ensured, and the misoperation probability is reduced.

Specifically, the control circuit bearing plate is used for bearing an embedded control circuit, a sensor conditioning circuit, a communication circuit and a first power supply conversion circuit of the rudder electronic system;

the embedded control circuit is used for generating four paths of steering engine control logics including PWM (pulse width modulation) and DIR (direct) according to steering engine sensing signals and external control signals by adopting a 'one-to-four' control program inside, and respectively controlling the motion of four brushless motors of the steering engine;

the first power conversion circuit is used for converting the voltage input from the outside and supplying power to the circuit unit on the control circuit bearing plate.

More specifically, the embedded control circuitry includes a processor STM32G474RET3 and corresponding peripheral circuitry;

the processor selects STM32G474RET3 of STM32G4 series of ST company, and supports FPU and DSP instruction set based on Cortex-M4 kernel, and the dominant frequency is as high as 170KHz. The size of the internal FLASH is 128Kbyte, and the working temperature is in the army temperature range of-40 to 125 ℃.

Processor capability calculation table

Serial number

Software unit

Name (R)

Operating position

Use of

Response time

1

Timer interrupt service function

ISR_TIMER

Main.c

Timing 0.5ms, 2ms, 4ms

120us

2

RS422 interrupt service function

ISR_RS422

RS422.c

Handling RS422 communication tasks

52us

3

CAN interrupt service function

ISR_CAN

CAN.c

Processing CAN communication tasks

44us

The compiled code is about 120K, the FLASH capacity of the processor MCU is 320K, and the FLASH resource utilization rate is 37.5%; RAM uses about 56K, the RAM capacity of MCU has 128K, RAM resource usage rate is 43.75%.

The voltage reduction switch power supply chip TPS73633 provides 3.3V stable direct current voltage for a hardware system. An NMOS in the TPS73633 linear regulator topology delivers a voltage follower configuration element. Using a low ESR as a stable output capacitor may allow even no capacitance at the chip periphery, providing a very low dropout voltage and low current ground terminal while maintaining a high precision voltage output.

The module acquisition module adopts an internal high-precision AD8066.

The isolation device comprises HCPL7851 and ADuM1400, wherein HCPL7851 is used for transmitting the secondary voltage of the drive circuit in an isolated mode, and ADuM1400 is used for isolating motor control quantity and direction signals.

More specifically, the sensor conditioning circuit is a constant-current type resistance-sensitive sensor signal conditioning circuit, and is used for conditioning sensor signals acquired by a resistance type RTD temperature sensor, a strain gauge type torque sensor and a power resistance type bus current sensor;

preferably, in the sensor conditioning circuit, since sensor signals such as temperature, torque, power and the like are all resistance-type, the sensor conditioning circuit can adopt a stable constant-value current source to generate a changed voltage for signal acquisition. The high-precision controllable current source used by the invention is LT3092, the maximum output current of the high-precision controllable current source is 200mA, the current output of 0.5 mA-200 mA is set through two resistors outside, and the current regulation performance is 10PPM/V. Taking a temperature sensor as an example, the system adopts a Pt1000 platinum resistor as a temperature sensor. The resistance value of the platinum resistor changes along with the change of the temperature, the change quantity of the resistance value is converted into the change quantity of the voltage, and then the temperature value is calculated. The circuit adopts 100K omega and 1K omega resistors to match with an LT3092 chip to generate 1mA current, and the voltage is amplified by 3.5 times after corresponding voltage is generated through a Pt1000 platinum resistor. The voltage range of the output end of the first OPA2211 operational amplifier is about 3-5.1V, and a subtraction circuit is added, so that the voltage of the AD1 is reduced to 0.5-2.6V, and the design and selection requirements are met.

The communication circuit comprises an RS422 and CAN double communication interfaces and a software protocol;

and a double communication interface and a software protocol are adopted, so that better product adaptability is achieved. LTM2885 and LTM2889 are respectively selected for the isolated communication chip.

The LTM2885 is a full-duplex isolated RS422 transceiver, a single power supply supplies power to both sides of an interface through an internally integrated isolated, low-noise, high-efficiency 5V output DCDC converter, the maximum data communication rate is 20Mbps, the receiver has a 1/8 unit load, and each bus can support up to 256 nodes.

LTM2889 is the isolation CAN transceiver of current mode, utilizes inside DCDC converter to supply power for interface both sides equally, supports flexible data rate, reaches 4Mbps.

The first power conversion circuit comprises a secondary power conversion and power monitoring circuit.

Specifically, the power conversion chip LTM8067 for secondary power conversion is packaged with 9mm × 11.25mm × 4.92mm bga, and each chip includes an isolation transformer, a control circuit, a power switch, and other supporting components. Only one resistor and input and output capacitors are required to complete the design.

The LTM8067 works in the range of 2.8V to 40V input voltage, and meets the requirement that a primary power supply is biased to 28V +/-3.5V. The flyback topology is adopted inside, and each device can adjust the output voltage to be higher than, lower than or equal to the input voltage. LTM8067 has an adjustable output voltage range of 2.5V to 24V, and can provide a load current of up to 450mA from a 5V power supply. The negative power supply of-5V is obtained from a 5V power supply by adopting an LTC1983-5 charge pump inverter, the DCDC converter LTC1983-5 adopting a reverse charge pump has the input voltage range of 2.3V-5.5V, the quiescent current of only 25uA, 100mA load current can be provided, short circuit and overheating protection are realized, the output voltage is-5V, and the power supply requirement of the bipolar operational amplifier is met.

The power supply monitoring LTC2947 has a monitoring resistor and a high precision power energy monitor inside, and an internal analog to digital converter is 14 bit accurate. The current, voltage, power, charge, energy can be measured. The voltage measurement range is-30A to 30A, the voltage measurement range is 0 to 15V, and the measurement precision reaches 0.5 percent. 6 power supplies for the electronic system are monitored and uploaded to the external controller in data form.

Power supply load capacity calculation table

Specifically, the driving circuit bearing plate is used for bearing a brushless motor driving circuit, a current monitoring circuit and a second power supply conversion circuit of the rudder electronic system;

the brushless motor driving circuit generates three-phase driving voltage required by the rotation of four brushless motors of the steering engine according to collected Hall sensing information of the rotor of the brushless motor and four steering engine control logics including PWM (pulse width modulation) and DIR (direct current) output by the embedded control circuit;

More specifically, the brushless motor drive circuit includes four identical motor drive sub-circuits; the drive logic generation chip UCC2626 of each motor drive sub-circuit generates three-phase drive voltage required by the rotation of the corresponding brushless motor according to the Hall sensing information of the rotor of the corresponding brushless motor and the PWM & DIR steering engine control logic output by the embedded control circuit.

The UCC2626 control chip is used as a control core, and hardware resources such as a Hall signal decoding circuit, a triangular wave oscillator, a comparator, a current sensing amplifier, an absolute value circuit and the like are arranged in the UCC2626 control chip, so that the design of the control circuit is simplified; the UCC2626 converts the Hall signal input by the position of the rotor into six paths of output for controlling an external power tube; the triangular wave oscillator and the comparison latch can provide voltage or current type PWM control; the UCC2626 may control the operating mode of the power tube; the internal integrated current amplifier can be used for current closed-loop control; a precisely controlled duty cycle output; the internal precision oscillator is used as the synchronous master clock source.

The gate drive of the drive power MOS of the brushless motor with the Hall of the embodiment adopts an STM32 chip, the output voltage of a pin is 3.3V and is far less than the gate-on voltage of a MOSFET (metal oxide semiconductor field effect transistor), and when the MOSFET is switched on, the drain-source level is the same, so that the gate-source voltage difference is required to be formed through voltage bootstrap. The scheme for realizing the driving of the MOSFET by the chip output level of the currently integrated MOSFET driving chip comprises the following steps:

the MOSFET uses a dedicated gate driver chip, such as DRV8353M, DRV10970 from TI; TLE7189F from Infineon, IRS23365DM; A3946K and A4935K from Allegro; SI9979 from VIHAY corporation. Compared with DRV835X series, DRV8353M adds a current feedback function, so the MOSFET gate driving of this embodiment adopts DRV8353M.

The current monitoring circuit comprises four same current monitoring sub-circuits; each current monitoring sub-circuit adopts an isolated sigma-delta modulator AD7403 to monitor the bus current of the corresponding brushless motor.

The isolated sigma-delta modulator AD7403 is suitable for precision current and voltage measurement in DC/AC power conversion applications. Higher signal-to-noise ratio can realize more accurate current and voltage measurement, and the performance of motor driving is improved by reducing torque fluctuation on a motor shaft.

Using an isolated sigma-delta type modulator allows for the use of smaller shunt resistors, thereby reducing heat loss in the shunt resistors while maintaining measurement accuracy. The AD7403 isolated sigma-delta modulator has the main characteristic of 5MHz to 20MHz external clock input rate; 16-bit no-missing codes; typical value of offset drift: 1.5uV/° C; an on-chip digital isolator; an on-chip reference voltage source; true bipolar analog input range: 320mV.

The second power conversion circuit adopts LTM8068, the LTM8068 and the TM8067 are serialized products, adopts 9mm x 11.25mm x 4.92mm BGA packages, and comprises an isolation transformer, a control circuit, a power switch and other supporting components. Only one resistor and input and output capacitors are required to complete the design. The creepage distance and the clearance of the pins and other characteristics enable the two devices to meet the requirements of ^ standard. LTM8068 includes an additional low noise linear regulator.

TM8068 has a low noise linear regulator at the output with an output voltage range of 1.2V to 18V. The linear voltage regulator reduces the ripple to 20VRMS when the output voltage is 300mA, thereby improving the noise performance when supplying power for high-accuracy signal conditioning and mixed signal chips. The drive's brushless motor logic chip UCC2626 is supplied with 5V and 15V power.

Specifically, each power circuit daughter board is used for bearing a three-phase inverter power circuit, a temperature monitoring circuit and a bottom layer power supply circuit of a brushless motor of the rudder power electronic system;

more specifically, the double N-MOS transistor is integrated in a DirectFET package. DirectFET uses surface mount technology to enable the source and gate to be directly connected to the surface of a silicon wafer. The surface is coated with a passivation material to protect and control the position, shape and size of the solder joint between the device and the substrate. The DirectFET packaging technology is adopted to realize the application design of high power density, and the inductance and the impedance are effectively improved in the aspects of thermal characteristics and electrical characteristics. DirectFET devices have a variety of housing sizes and device geometries there are currently 3 sizes: s size 4.88 x 3.95; m size 6.35 x 5.05; s size 9.15 × 7.10. The 3 sizes are selected from 19 products, wherein 7 types of products including ST, SQ, SJ, SH, S1, S2, SB and the like are packaged in the small size, 9 types of products including MT, MX, MP, MQ, MN, MZ, MU, M2, M4 and the like are packaged in the medium size, and 3 types of products including L4, L6, L8 and the like are packaged in the large size.

MOSFET model selection table

Serial number	Type of D-FET	Voltage (V)	Current (A)	Encapsulation (F)	Layout (S)
						1	IRF6645	100	25	S	5
2	IRF6644	100	57	M	5
						3	IRF6722	30	56	M	5
4	IRF7732	40	58	M	5
						5	IRF7732	40	55	/	5
6	IRF6297	20	15	S	6
						7	IRF6614	40	55	S	5
8	IRF6662	100	47	M	5
						9	IRF7647	100	24	/	5
10	IRF6637	30	59	M	5
						11	IRF6623	20	55	S	5
12	IRF6617	30	55	S	5
						13	BSF104N08	80	50	M	2
14	BSF134N10	100	40	S	2
						15	BSF450NE7	75	15	S	2

The energy storage capacitor of the power MOS tube adopts CAK39H-T3-60150uF-K. CAK39H-T3-60150uF-K is a small-size long-life airtight non-solid electrolyte all-tantalum capacitor with reliability index, and the T2 size is 16.28 x 7.14mm. When the withstand voltage is 60V or 63V, the capacitance value is 150uF, one circuit board is mounted on each circuit board, 4 circuit boards are mounted on each circuit board in total, and the total capacitance value is 450uF, so that the design requirement is met.

The temperature monitoring circuit adopts a resistance RTD temperature sensor to monitor the heat dissipation and the temperature of the power device;

RTDs are passive sensors that require an excitation current to generate an output voltage. The output level of an RTD varies from tens of millivolts to hundreds of millivolts, depending on the RTD chosen. The AD7124-8 used a constant current source of 500 uA. The conversion rate of AD7124-8 was: 192KSPS. Designed for slow speed applications requiring extremely high accuracy, such as temperature and pressure measurements. AD conversion chips AD7785, AD7793, AD7794, AD7124 and MAX1403 with constant current sources. The special thermistor temperature measurement chip: LTC2983, MAX31865.

And the bottom layer power supply circuit is used for converting the voltage input from the outside and supplying power to the circuit unit on the power circuit sub-board.

The bottom layer power supply cable is provided with a soft belt after shielding treatment, and an external 28V power supply circuit is distributed to four bottom layer power supply circuits. And the soft belt subjected to shielding treatment is wrapped by the shielding layer. The normal sudden change of current in the power module can cause the electromagnetic compatibility problem, realizes the effective parcel of electromagnetic signal through the sealed of heat dissipation shell with the power MOS pipe.

A specific technical solution of this embodiment further includes a steering engine; the steering engine adopts the electronic system for the compact rudder in the technical scheme of the embodiment as an electronic system of the steering engine, and comprises an integrally formed rigid-flex printed board; the rigid board area of the rigid-flex printed board comprises a control circuit bearing board, a driving circuit bearing board and a power circuit bearing board;

In summary, the electronic system for the compact rudder and the steering engine disclosed by the embodiment of the invention adopt the planarization design of the rigid-flex printed board, and the three-dimensional layout after bending replaces the connection of internal cables, so that the structure is more compact, the space occupation ratio is small, and the manufacturability is more optimized; due to the three-dimensional design of the rigid-flexible printed board, the assembly time is saved, the processes of electric fitting welding and field inspection are omitted, the specific gravity of the product quality is increased due to the design guarantee, and the process guarantee is weakened; the personnel cost is saved, the quality is ensured, and the misoperation probability is reduced. The device is beneficial to mass production, has high efficiency and yield, ensures quick design and quick assembly, and provides powerful support for modernization of equipment.

While the invention has been described with reference to specific preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims

1. A compact electronic system for rudders is characterized by comprising an integrally formed rigid-flex printed board; the rigid board area of the rigid-flex printed board comprises a control circuit bearing board, a driving circuit bearing board and a power circuit bearing board;

the control circuit bearing plate is connected with the driving circuit bearing plate through a first flexible plate; the driving circuit bearing plate and the power circuit bearing plate are connected through a second flexible plate;

2. The compact electronic system for rudders as claimed in claim 1, wherein said control circuit board and drive circuit board are both a one-piece rigid circuit board;

one end corresponding to the long edge of each L-shaped flexible plate is bent 90 degrees towards the opposite direction of the position of the control circuit bearing plate, one end of the short edge is bent 90 degrees inwards, so that the four power circuit sub-boards are respectively vertical to the drive circuit bearing plate, and the spatial positions among the four power circuit sub-boards are in a cross shape.

3. The compact rudder electronics system of claim 2 further including a mounting structure; the mounting structure comprises a base, four vertical mounting plates and a horizontal mounting plate;

4. The compact electronic system for rudders as claimed in claim 2,

the control circuit bearing plate is used for bearing an embedded control circuit, a sensor conditioning circuit, a communication circuit and a first power supply conversion circuit of the rudder electronic system;

the embedded control circuit is used for generating four paths of steering engine control logics including PWM (pulse width modulation) and DIR (direct current) according to the steering engine sensing signals and external control signals by adopting a one-to-four control program in the embedded control circuit, and is respectively used for controlling the motion of four brushless motors of the steering engine;

5. The compact electronic system for rudders as claimed in claim 4, wherein the embedded control circuitry comprises a processor STM32G474RET3 and corresponding peripheral circuitry;

6. The compact electronic system for rudders as claimed in claim 2,

the driving circuit bearing plate is used for bearing a brushless motor driving circuit, a current monitoring circuit and a second power supply conversion circuit of the rudder electronic system;

7. The compact electronic system for rudders as claimed in claim 6, wherein said brushless motor drive circuit comprises four identical motor drive sub-circuits; each motor driving sub-circuit adopts a driving logic generation chip UCC2626, and generates three-phase driving voltage required by the rotation of the corresponding brushless motor according to the Hall sensing information of the rotor of the corresponding brushless motor and the PWM & DIR steering engine control logic output by the embedded control circuit;

8. The compact electronic system for rudders as claimed in claim 2,

each power circuit sub-board is used for bearing a three-phase inversion power circuit, a temperature monitoring circuit and a bottom layer power supply circuit of a brushless motor of the rudder power electronic system;

the three-phase inverter power circuit adopts a driving tube and a power MOS tube packaged by DirectFET to carry out driving amplification and power amplification on the input three-phase driving voltage and outputs the three-phase driving voltage to the corresponding brushless motor;

the temperature monitoring circuit adopts a resistance type RTD temperature sensor to monitor the heat dissipation and the temperature of the power device.

9. The compact electronic system for rudders as claimed in any one of claims 1 to 8, wherein said first and second flexplates are further adapted to act as signal transmission channels between rigid plate areas;

10. A steering engine comprising the electronic system for a compact rudder according to any one of claims 1 to 9.