Hardware Development Of Ultra-short Baseline Positioning System Based On Domestic Components

China has a vast coastline,and positioning sonar has high-precision positioning capabilities,which can directly provide absolute position coordinates and trajectories for various deep-sea exploration equipment,playing a significant role in the civil and military fields.As the core of system hardware,the performance of chip devices directly determines the stability and reliability of the entire system.At present,Chinese sonar positioning system mainly uses foreign chips.With the establishment of the American Semiconductor Alliance,the global chip situation has accelerated and worsened.In order to ensure the safety and stability of ocean defense and ocean development,it is necessary to develop hardware units for ultrashort baseline positioning systems by using domestic chips.The development and application of foreign chips are mature.Due to the development habits and market performance-to-price ratio,there are few design cases for domestic chips used by chinese researchers,and the lack of reference materials makes it difficult to localize the system hardware.According to the board level characteristics of the sonar hardware unit and the current status of chip technology at home and abroad,the overall scheme design of the system is carried out.The system is mainly divided into four parts: transmitter,receiver,digital board,and power supply unit.The specific work content and results are as follows:(1)Analyze and calculate the technical indicators of the transmitter,and design the isolation circuit,the drive circuit,the power amplifier circuit,the transformer and matching circuit.Select domestic chips according to requirements,for the power amplifier circuit,Beijing Yuxiang’s CS86N10 field-effect transistor is superior to the same type of foreign IRF3710 S in terms of technical parameters such as switching time,drain source withstand voltage,and conduction loss;As for the drive circuit,the JS2110 of CETC58 is used as a chip to replace the Infineon IR2110.The drive current and heat dissipation parameters are superior to foreign chips,ensuring the stability of the transmitter during long-term operation.According to the characteristics of the domestic transducer,the transformer and matching circuit is designed to ensure the high sound source level of the transmitter.The feasibility of the scheme is confirmed through the transmitter circuit simulation.The test results show that the maximum sound source level of the transmitter based on domestic chips reaches 190 d B or more,with an average value higher than that of the transmitter based on foreign chips during the same period,and the efficiency reaches 79%,meeting the system transmission requirements.(2)Analyze and calculate the technical indicators of the receiver,and design the front-end amplifier,variable gain amplifier,front-end filter,variable gain amplifier,back-end filter,and final amplifier circuits.Through the analysis of low noise,the design is carried out from the aspects of gain distribution,low noise devices,power filter,PCB design,etc.The instrument amplifier and operational amplifier from Guizhou Zhenhua and the analog switch from CETC24 are selected to design the amplification circuit and filter circuit,the simulation results are consistent with the theory.Independent test of key chips has verified that the chips perform well in the actual environment and can meet requirements.The circuit board test results show that the receiver based on domestic chips can achieve channel phase consistency of ±1° and amplitude consistency of ±0.2d B high-precision adjustment.The filter bandwidth is 7k Hz,and the amplifier can achieve variable gain of 44 d B,54 d B,62 d B,and 72 d B.The circuit board power is 0.24 W,and the maximum equivalent input noise is only 1.5u V.Compared with the receiver based on foreign chips in the same period,it can be seen that the performance is good.(3)According to the technical indicators of the digital board,the FPGA minimum hardware system,the data acquisition circuit,the network communication circuit and the serial communication circuit are designed to achieve the functions of collecting,converting,and transmitting received signals.According to the circuit requirements,we selecte the FPGA series of Pangomicro Logos,the Giga Device FLASH,the Huowei Military Digital Power Supply Board,Chenjing electronic active crystal oscillator,the SAD9240 of CETC24,the differential operational amplifier of CETC24,the SM5100 network interface chip of Shenzhen Statemicro Electronics,the network transformer of Zhongshan Hanren Electronics,the CBM232 and CBM485 serial communication chips of Corebai for domestic chips such as the NSI8242 dedicated digital isolation chip of the nano core micro.The system test results show that the digital board based on domestic chips can achieve data acquisition functions,the collected signals have good phase consistency,and the network communication and serial communication functions of the digital board are normal.The digital board can output good transmitting pulses for the transmitter.(4)According to the 28V/20 A power supply condition of the system,the Huowei power supply chip is used to design four parts: a transmitting power supply conversion board,a transmitting on-board power supply module,a receiving on-board power supply module and a digital power supply conversion board.Reduce the involvement of noise from the source of the system by adding a power filter circuit.The test results show that the voltage of each power module is accurate and the ripple noise is small,which can meet the power supply requirements of the system.After the hardware circuit design is completed,a circuit board PCB design is performed.The test results of each circuit board prove that the hardware unit of the ultra short baseline positioning system based on domestic components meets the index requirements.The system has practical application value.