CN105487533A - Vehicle-mounted diagnostic data sharing terminal system - Google Patents

Abstract

The invention discloses a vehicle-mounted diagnostic data sharing terminal system. The system comprises a vehicle-mounted diagnostic data sharing terminal loaded with software, and the vehicle-mounted diagnostic data sharing terminal is connected with a power supply and a debugging interface used for debugging the software performance through an auxiliary peripheral circuit and further connected with a vehicle-mounted computer and a diagnostic data cloud and performs two-way communication. The vehicle-mounted diagnostic data sharing terminal system further comprises an MCU module which is connected with a vehicle-mounted computer interface subsystem, a cloud sharing interface subsystem, a local storage subsystem and the auxiliary peripheral circuit. The system can be directly connected with the vehicle-mounted computer in a butting mode, acquires diagnostic data through information interaction with the vehicle-mounted computer, achieves real-time sharing of the diagnostic data through wireless communication according to the system requirement and has the enough data handling capacity for coping with the flow of the diagnostic data.

Description

A kind of On-Board Diagnostics (OBD) data sharing terminal system

Technical field

The invention belongs to Communication and Transportation Engineering technical field, be specifically related to a kind of On-Board Diagnostics (OBD) data sharing terminal system.

Background technology

Diagnostic data shared terminal equipment is that diagnostic data cloud is shared and data collector foremost in in-circuit diagnostic system, it directly docks with truck-mounted computer, by obtaining diagnostic data with the information interaction of truck-mounted computer, and realized the Real-Time Sharing of diagnostic data by radio communication according to the demand of system.

The diagnose interface form of truck-mounted computer is Ethernet interface, and diagnostic procedure communicates according to Ethernet ICP/IP protocol.According to the technical indicator in signal system product technical documentation, the diagnostic data amount of generation per hour is no more than 50 megabyte.Terminal device must adapt to interface shape and the communication protocol of truck-mounted computer, and possesses abundant data-handling capacity to tackle the flow of diagnostic data.

The diagnostic data that terminal device should possess truck-mounted computer produces quickly and reliably processes and is forwarded to the ability in data high in the clouds, to meet the needs that inline diagnosis and fault are investigated fast.Cloud sharing functionality, while consideration data traffic, fully should ensure integrality and the reliability of data, be strict controlled in misdiagnosis rate and the false alarm rate index of radiodiagnosis x.Meanwhile, feasibility and the cost of design is fully taken into account from engineering viewpoint.

In addition, consider that cloud sharing functionality is for communication and the dependence of network environment, in order to guarantee the integrality of data further, being convenient to transport pipe personnel and carrying out daily servicing, terminal device should by the diagnostic data real-time storage that receives on the storage medium of this locality.The design concept of flight (navigation) registering instrument of reference aviation and navigational field, this storage medium should be reliably firm, when there is extreme situation or major accident, for crash analysis and hidden troubles removing provide reliable basis.

In sum, urban rail car carries diagnostic data cloud shared terminal equipment and should meet following function:

1) with the communication interface of truck-mounted computer; 2) appropriate wireless vehicle ground communication function; 3) data local storage function.While stating function in realization, the running environment of urban rail transit vehicles should be taken into full account from engineering viewpoint, meet all technical restriction of urban rail transit vehicles electronic electric equipment, adapt to the power supply system of mobile unit.

In recent years, along with the technical requirement of modern project improves constantly, micro control system is faced with more and more stern challenge in arithmetic capability, volume, power consumption etc.In this context, embedded system due to its volume and power consumption controlled, arithmetic capability is comparatively strong, and the construction cycle is short, and use flexibly, the features such as strong adaptability, become the main way of realization of the control system based on microcontroller gradually.

Embedded system is for the purpose of specialized application, and based on computer technology, software and hardware can be cut out, and the system that is adapted to has the dedicated computer system of strict demand to function, reliability, cost, size, power consumption etc.In embedded systems, embedded software and embedded bottom hardware are integrated in one, and realize the high unity of software restraint.In addition, because embedded system can be highly self-defined, its application scenarios spreads all over each fields such as Industry Control, medical treatment, network service, automobile, consumer electronics product, office automation product.Because the application of embedded system is along with the change constantly development and evolution of demand, the definition of " embedded system " is also continuous Change and Development.Embedded system has following features usually:

1) embedded system is existing more limited for personal computer (PC) on hardware and software feature.That has benefited from software and hardware aspect can cutting, its availability of embedded system software and hardware tune with better function and cost performance;

2) embedded system designs for performing special function.Relative to PC, embedded system more emphasizes its specificity;

3) embedded system is the computer system than the computer system of other types with more high-quality and reliability requirement.Because embedded system application often relates to safety (as Industry Control, automobile, traffic, medical treatment etc.), once there is unexpected situation, likely will produce serious consequence, and PC is used for calculating and the information processing of auxiliary people, actual effect to a certain degree can be tolerated.

In recent years, novel architecture tool (reference model) is also introduced into embedded system field.This system structure model is that the layering (modularization) of embedded system syllabus and content represents in essence.By by the component visualization of embedded system inside and being grouped into " layer ", the architecture of complex embedded system will become more clear and easy understand, also for design brings many facilities.Embedded System Structure model representation, all embedded systems all have common point in its structure.

Hardware layer is the logical layer that all embedded systems all must comprise, and it comprises and is positioned at Main physical parts all on embedded circuit board; System software layer mainly refers to the bottom software run for supervisory computer software and hardware resources, coordination multithreading run on hardware layer, system software layer has certain versatility usually, generally include device driver and operating system, the latter's this part in the not very complicated embedded system of function is not necessary; Application software layer refers to the application software being directly used in and realizing embedded system function, is the carrier of embedded system expection logic function, in minority for being optional in the embedded system demonstrating, impart knowledge to students, study.

Consider function and the performance requirement of municipal rail train On-Board Diagnostics (OBD) data sharing terminal device, embedded system due to its software and hardware system can be highly self-defined, function can cutting, power consumption is controlled, volume is controlled, the feature of the aspects such as flexible design, becomes the best way of realization realizing diagnostic data shared terminal equipment.

Therefore, need to propose a kind of On-Board Diagnostics (OBD) data sharing terminal system and farthest can meet vehicle-mounted data amount to the intrasystem data-handling capacity demand of shared terminal.

Summary of the invention

In view of the inconvenience that above-mentioned prior art exists, the object of the invention is to propose a kind of On-Board Diagnostics (OBD) data sharing terminal system, this system can directly be docked with truck-mounted computer, by obtaining diagnostic data with the information interaction of truck-mounted computer, and realized the Real-Time Sharing of diagnostic data by radio communication according to the demand of system, possess abundant data-handling capacity to tackle the flow of diagnostic data.

Object of the present invention, to be achieved by the following technical programs: a kind of On-Board Diagnostics (OBD) data sharing terminal system, comprise the On-Board Diagnostics (OBD) data sharing terminal being mounted with software, described On-Board Diagnostics (OBD) data sharing terminal is connected with power supply and the debugging interface for debugging software performance by ancillary peripheral circuit, and described On-Board Diagnostics (OBD) data sharing terminal is also connected with truck-mounted computer (VOBC) and diagnostic data cloud and carries out two-way communication.

Preferably, described On-Board Diagnostics (OBD) terminal data shared terminal system also includes MCU module, and described MCU module is shared interface subsystem, local storage subsystem and ancillary peripheral circuit respectively and is connected with truck-mounted computer interface subsystem, cloud.

Preferably, described truck-mounted computer interface subsystem is for providing with the Ethernet interface of onboard system information interaction and being connected by FMC bus with described MCU module.

Preferably, described MCU module and described cloud are shared interface subsystem and are connected by UART (universal asynchronous serial transceiver), and by On-Board Diagnostics (OBD) data upload to high in the clouds.

Preferably, described MCU module is connected with described ancillary peripheral circuit.

Preferably, described truck-mounted computer interface subsystem is connected with described truck-mounted computer (VOBC).

Preferably, described truck-mounted computer interface subsystem is set up TCP with described truck-mounted computer and is connected, receive the packet comprising diagnostic data information that truck-mounted computer sends, local tcp protocol stack is utilized to be resolved according to ICP/IP protocol by packet, data field content in being wrapped by TCP is stored in local FIFO memory block, and inform MCU module by the form of terminal affair, wait for the call instruction of MCU module; When MCU module access truck-mounted computer interface subsystem, the information received is returned to MCU module according to certain rule by subsystem, and empties local cache district, waits for the arrival of follow-up data.

Preferably, described cloud is shared interface subsystem and is connected with diagnostic data cloud.

Preferably, described local storage subsystem and SD link and connect, and SD card is by the read-write process of SD card managing chip by SPI Interface Controller data, and SD card management managing chip periphery is provided with uncoupling electric capacity and filtering circuit.

Outstanding effect of the present invention is: this system can directly be docked with truck-mounted computer, by obtaining diagnostic data with the information interaction of truck-mounted computer, and realized the Real-Time Sharing of diagnostic data by radio communication according to the demand of system, possess abundant data-handling capacity to tackle the flow of diagnostic data.The diagnostic data that terminal device possesses truck-mounted computer produces quickly and reliably processes and is forwarded to the ability in data high in the clouds, to meet the needs that inline diagnosis and fault are investigated fast.Cloud sharing functionality, while consideration data traffic, fully can ensure integrality and the reliability of data, be strict controlled in misdiagnosis rate and the false alarm rate index of radiodiagnosis x.

Below just accompanying drawing in conjunction with the embodiments, is described in further detail the specific embodiment of the present invention, is easier to understand, grasp to make technical solution of the present invention.

Accompanying drawing explanation

Fig. 1 is On-Board Diagnostics (OBD) data sharing terminal system Organization Chart of the present invention;

Fig. 2 is that PMC bus of the present invention writes data procedures figure;

Fig. 3 is MCU supervisory electronic circuit schematic diagram of the present invention;

Fig. 4 is download program interface circuit schematic diagram of the present invention;

Fig. 5 is W5300 memory-mapped schematic diagram of the present invention.

Embodiment

Object of the present invention, advantage and disadvantage, by for illustration and explanation for the non-limitative illustration passing through preferred embodiment below.These embodiments are only the prominent examples of application technical solution of the present invention, allly take equivalent replacement or equivalent transformation and the technical scheme that formed, all drop within the scope of protection of present invention.

As shown in Figure 1, a kind of On-Board Diagnostics (OBD) data sharing terminal system, comprise the On-Board Diagnostics (OBD) data sharing terminal being mounted with software, described On-Board Diagnostics (OBD) data sharing terminal is connected with power supply and the debugging interface for debugging software performance by ancillary peripheral circuit, and described On-Board Diagnostics (OBD) data sharing terminal is also connected with truck-mounted computer (VOBC) and diagnostic data cloud and carries out two-way communication.

Described On-Board Diagnostics (OBD) terminal data shared terminal system also includes MCU module, and described MCU module is shared interface subsystem, local storage subsystem and ancillary peripheral circuit respectively and is connected with truck-mounted computer interface subsystem, cloud.

Described MCU module, as the core of On-Board Diagnostics (OBD) data sharing terminal system, is the core hinge that diagnostic data receives, processes and forward, and is also the hinge coordinating work-based logic and sequential between each subsystem.Microprocessing unit (MicroControlUnit, MCU) is the core of Embedded computer system system, and the arithmetic capability of MCU chip and interface type directly determine the performance of system.In order to ensure the steadily normal work of MCU chip, be convenient to debugging and the management of equipment, embedded system also needs the auxiliary circuit of a series of cooperation MCU chip.Above-mentioned auxiliary circuit and MCU chip constitute MCU module.In the design of diagnostic data shared terminal, MCU module mainly comprises MCU chip, internal storage location, MCU supervisory electronic circuit and download program interface.According to the system architecture of diagnostic data shared terminal, MCU module needs to be connected by interfaces such as SPI, UART, FMC buses with three large subsystems.In order to ensure that the data of truck-mounted computer interface subsystem are processed fast, the dominant frequency of MCU also should do appropriate consideration.

In the present embodiment, diagnostic data shared terminal selects ARMCortex-M4 series kernel as the MCU kernel of native system.Cortex-M4 series microprocessor is novel 32 low costs, the high performance general purpose microprocessor kernel that ARM company releases, this kernel that its outstanding computing power, low-power consumption and low cost are is widely used in the fields such as Industry Control, communications and transportation and automotive electronics, be the Typical Representative of current main-stream micro-processor kernel, represent the trend of present microprocessor kernel development.Cortex-M4 kernel has following characteristic:

1) Cortex-M4 is the processor based on Harvard structure, its use two independently memory module deposits instruction and data respectively, use two buses respectively as the communication of CPU and two memory module, the processor that this parallel processing structure makes Cortex-M4 kernel compare von Neumann mutually in arithmetic speed has a clear superiority in simultaneously;

2) dominant frequency reaches as high as 180MHz;

3) arithmetic capability is up to 225DMIPS (1.25DMIPS/MHz);

4) support Thumb-2 instruction set, bring the performance of 32 bit processors with the code density of 16;

5) monocycle multiplying order and hardware division instruction is supported;

6) built-in interruptable controller fast, possesses superior enforcement characteristic, only needs 6 cpu cycles the time delay between interruption, also only needs 6 cpu cycles from the time that low-power consumption mode wakes up.

Select the STM32F4 series microprocessor of ST Microelectronics's production as MCU in the present embodiment.Design according to diagnostic data shared terminal system architecture, MCU module needs at least 2 group SPI controllers, 3 groups of UART controllers and one group of variable Memory Controller Hub (FlexibleMemoryControl, FMC) altogether with three large subsystems and linking of ancillary peripheral circuit.Comprehensive above-mentioned interface requirement, selects STM32F429ZGT6 chip as MCU in the present embodiment.STM43F429ZGT6 adopts LQFP144 encapsulation, has 144 I/O ports.Its performance comprises:

1) the internal data store space of 1MB;

2) possess outside variable Memory Controller Hub (FlexibleExternalMemoryController), support the highest 32 bit data bus and 24 bit address buses, support the internal memory of Flash/NOR/NAND tri-kinds of forms.

3) the power supply standard from 1.8V to 3.6V is supported;

4) support sleep, suspend and dormancy three kinds of low-power consumption modes,

5) built-in 12 timers, toggle rate reaches as high as maximum 12 16 bit timers of 180MHz or 2 32 bit timers;

6) support the multiple debugging interface comprising JTAG and SWD, support the EmbeddedTraceMacrocell debud mode that Cortex-M4 is special simultaneously;

7) support 6 groups of SPI interfaces or 2 groups of I2S interfaces, 3 groups of I2C, 4 groups of universal synchronous/asynchronous serial data transceiver (UniversalSynchronous/AsynchronousReceiver & Tansmitter simultaneously, USART), 2 groups of CAN interfaces and SDIO interface;

8) maximum 114 can be used for the multi-usage input/output end port (GeneralPurposeIn/Out, GPIO) comprising external interrupt process

9) built-in true random number maker and CRC check unit.

In addition, STM43F429ZGT6 also possesses the Premium Features such as USB-OTG, liquid crystal display parallel interface, owing to not dropping into application in the design of diagnostic data shared terminal, repeats no longer one by one herein.Cortex-M4 kernel is connected by ahb bus with each peripheral hardware.

For ensureing the stable of MCU chip, system has selected the passive crystal oscillator of 8M as external clock reference.In order to protect IC is from the impact of power-supply fluctuation and external interference, near the power pins of MCU, all arrange uncoupling electric capacity.

According to the technical information of onboard system manufacturer, it is per hour that the diagnostic data amount that onboard system produces is no more than 50MB, but it produces speed and instability, objectively there is the possibility of rapid accumulation in the mass data short time.In order to tackle above-mentioned situation, ensureing availability and the stability of equipment, ensureing data security, MCU module is provided with the outer internal storage location of sheet.FMC bus is a kind of conventional master---from formula memory expansion interface, is usually made up of auxiliary signals such as the choosing of address bus, data bus and sheet, enable, the high/low byte controls of read/write.MCU is bus host normally, and other equipment such as internal memory usually used as FMC from equipment.The bus signals type of FMC is as shown in table 1.In table, sheet choosing, the signal such as enable are generally Low level effective, usually with N before its title.

Table 1FMC bus signals

A[25:0]	Address bus
		Data[31:0]	Data I/O
NEx	Chip selection signal Enable
		NOE	Output enable signal Output Enable
NWE	Data write enable signal Write Enable
		NBL[1:0]	High/low byte control Lower-byte Control

Address bus is that MCU informs the information channel of the memory cell address by read/write to FMC bus apparatus, by FMC host computer control.Data bus is the data message passage in read/write processes in internal storage location.NEx is chip select signal, and and if only if when this signal is low level, and FMC bus apparatus is reacted to the control of MCU; Be necessary for each FMC in circuit design process and arrange a NEx signal wire from machine, by FMC main frame by controlling this signal coordinating respectively from the work schedule of machine.NOE and NEW is respectively from the input (reading) of machine and input (writing) enable signal, and both repel mutually, are Low level effective.NBL [1:0] is the control line of a group two, when FMC main frame access 16 internal memories by 8 bit data bus or by 16 internal storage access, 32 internal memories time, for coordinating the priority input of high low byte.When NBL is 10B, represent that the data of current read/write are high byte, 01B is low byte, will not do any reaction during 11B or 00B from machine.

When MCU is by FMC bus access memory chip, needs operating sheet choosing one by one, Writing/Reading is enable, by address bus Input Address with input high/low byte control signal respectively, carried out the read-write of data by data bus.In writing, save as example, in the internal memory write cycle, the state of each signal as shown in Figure 2.

MCU operates chip selection signal and sets low, and require that controlling high/low byte selects signal to put high/low according to program, controlling address bus is the current memory cell address being about to write.Due to current execution is write operation, so will read enable setting high.After above-mentioned action completes, main frame needs wait correctly to read address from machine, and this stand-by period is commonly called address and is loaded into the time (AddressSetupTime).When setting low when host computer control NWE signal and write data to data bus, from machine, read the content in current data bus, and write correspondence memory unit.The state of bus data and NWE needs to keep a period of time correctly to read data to wait for from machine, and this stand-by period is called that data are loaded into the time (DataSetupTime).In order to ensure the reliably complete of digital independent, data after the playback of NWE signal, can be kept the chip period that extra by main frame usually again.

Select IS62WV102416ALL type static RAM (StaticRandomAccessMemory, SRAM) of ISSI company as the outer internal memory of sheet of MCU module in the present embodiment.The maximum 20 bit address buses of SRAMIS62WV102416ALL chip support and 16 bit data bus, inside is integrated with 1,000,000 16 storage unit, is equivalent to 2MB internal memory.IS62WV102416ALL is connected with MCU chip by FMC bus, and MCU module can access memory space easily, realizes the expansion of storage space, increases buffer capacity, to tackle mass data accumulation in short-term.

In order to ensure the stability of system, increasing system monitor circuit in system controller outside, when system is surprisingly collapsed due to external impact and system software, can guidance system reset restart.Supervisory electronic circuit is connected with core MCU by WDI with RESET two signal wires, and circuit is also known as " house dog ".CPU periodically sends " feeding dog " signal to supervision chip by WDI pin, then supervisory electronic circuit does not do action; If supervisory electronic circuit presets at one the signal not receiving MCU in the reset cycle, then think that unusual condition has appearred in MCU, software collapses, then activate RESET signal guidance MCU and reset.The author selects CAT706SVI as supervisory electronic circuit acp chip herein.MCU supervisory electronic circuit schematic diagram as shown in Figure 3.

Download program interface is the bridge of chip software and hardware combining.Joint test working group (JointTestActionGroupJTAG) is a kind of international standard test protocol by IEEE1149.1 operating such, is mainly used in download program and the on-line debugging of chip internal.JTAG is burning and the debugging interface of the most main flow of the chip products such as current MCU, DSP, FPGA, CPLD.Core MCUSTM32F429 chip provides jtag interface.Jtag interface standard-required comprises TMS, TCk, TDI, TDO tetra-signal wires, and SM32 chip also requires that reset (RST) signal wire is some simultaneously.Jtag interface circuit as shown in Figure 4.

Described truck-mounted computer interface subsystem is connected with described truck-mounted computer (VOBC).Described truck-mounted computer interface subsystem is for providing with the Ethernet interface of onboard system information interaction and being connected by FMC bus with described MCU module.

Described truck-mounted computer interface subsystem is the door realizing information interaction of diagnostic data shared terminal equipment and truck-mounted computer.This truck-mounted computer interface subsystem is set up TCP with truck-mounted computer and is connected, receive the packet comprising diagnostic data information that truck-mounted computer sends, local tcp protocol stack is utilized to be resolved according to ICP/IP protocol by packet, data field content in being wrapped by TCP is stored in local FIFO memory block, and inform MCU module by the form of interrupt event, wait for the call instruction of MCU module.When MCU module access truck-mounted computer interface subsystem, the information received is reported to MCU module according to certain rule by subsystem, and empties local cache district, waits for the arrival of follow-up data.

In truck-mounted computer interface subsystem, the realization of ICP/IP protocol is the Core Feature of this system.This function is mainly reflected in: when receiving extraneous TCP as TCP server and connecting and disconnect request, can automatically make correct response; When receiving extraneous tcp data bag, can correctly resolution data bag, verify its validity, and the key message extracted wherein calls for MCU module; After the data receiving MCU send instruction, it is packed with correct form and sends.A large amount of chip computational resources is often needed, often along with poor real-time by software simulating above-mentioned functions.

In the design of this truck-mounted computer interface subsystem, in the present embodiment, select the core processor of W5300 chip as system of WIZnet company.W5300 is the single-chip devices of a 0.18 μm of CMOS technology, internal hardware is integrated with integrated 10/100M ethernet controller, MAC and ICP/IP protocol stack, inner phaselocked loop exports and reaches 150MHz, can realize Ethernet/Internet very easily and connect.Due to its hard-wired protocol stack, its handling property other solutions by software simulating protocol stack far super.

The host interface that W5300 chip provides first level address to access, by the highest 16 bit data bus and its internal register space of 10 bit address bus access.In this mode, deviser uses variable Memory control (FlaxibleMemoryControl on main frame usually, FMC) function the memory headroom of this kind of chip is mapped in the storage space of MCU main frame, and then can the internal memory of access chip easily when programming.The memory mapped space of W5300 amounts to 0x400 byte, mapping address in the middle of main frame is expressed as the form of base address (BasicAddress)+side-play amount, that is: the base address+W5300 register offset amount of register physical address=host memory space.

The memory headroom of W5300 is by mode register (ModeRegisters), and general-purpose register (CommonRegisters) and port register (SOCKETRegisters) three part form.The distribution of its memory headroom and separately side-play amount are as shown in Figure 5.Mode register amounts to 2 bytes, for arranging the interface shape of W5300 and main frame, data bit width, and the basic model parameters such as reading and writing data accessing time sequence parameter.

General-purpose register amounts to 254 bytes, can be used for configuration packet and contains the key parameter of the Ethernet Hosts such as local mac address register, gateway address register, local IP address register and comprise the configuration informations such as interrupt register, each buffer to ports district size configure register, pin configuration register.This component register content bears the function of basic guide property usually in the interactive process of W5300 and main frame.

Port register is for being divided into 8 groups, 8 ports of corresponding W5300.Often organize register space and amount to 64 bytes, structure is identical.Host access port register can read or configure information such as comprising port mode, Port interrupts type, port numbers, destination port number, Target IP, or sends specific instruction by writing particular value in port command register to W5300.Especially, for the consideration of the convenience of stability and exploitation, the transmission of W5300 and receive spatial cache and cannot directly access.When mainframe box W5300 proposes send request of data or receive request of data, need by transmission (reception) fifo register in port register, by byte-by-byte for the data in W5300 spatial cache taking-up.W5300 will detect the process of main frame read operation in fifo register automatically, and automatically upgrades register data.

W5300 is enable by FMC bus and supporting choosing, read/write, interruption, reset equisignal line are connected with MCU, and therefore interface board is provided with two pieces of 40Pin plugs and matches with socket base plate, by above-mentioned signal transmission to MCU pin.Interface board is also provided with simultaneously RJ45 connector to be connected with external ethernet cable.Also be provided with the devices such as some uncoupling electric capacity, filtering circuit, crystal oscillator around W5300 and RJ45 connector, the safe and stable operation for chip provides necessary guarantee.

Described MCU module and described cloud are shared interface subsystem and are connected by UART (universal asynchronous serial transceiver), and by On-Board Diagnostics (OBD) data upload to high in the clouds.Described cloud is shared interface subsystem and is connected with diagnostic data cloud.

Cloud is shared interface subsystem and is mainly born by On-Board Diagnostics (OBD) data upload to high in the clouds, communicates, realize the function of diagnostic data Real-Time Sharing with upper cluster of server.It is feasible for setting up online easily extensible, the online data-sharing systems of fault tolerant based on internet.Based on the movability that urban railway transit train runs, the wireless remote transmission of data is necessary.Existing communication can realize the wireless remote transmission of data, and the actual needs of necessary coupling system, considers the factors such as its reliability, practicality and application cost, select suitable transmission mode herein.The wireless communication technology of main flow comprises: based on the wireless local area network technology of 802.11, wireless digital broadcasting station, and GSM (note), GPRS and the 3G being representative with W-CDMA technology, its technical characterstic is as shown in table 2.

Table 2 main flow wireless communication technology characteristic comparing

Based on the WLAN technology maturation of 802.11, transmission is stable, is widely used; But its single device coverage is less, need to cover WLAN access device completely in urban track traffic, cost is higher; Especially, contemporary cities track traffic has adopted communication-based train control system (CommunicationBasedTrainControl all, CBTC), the wireless data communications of this system also adopts 802.11 standards and is operated in 2.4GHz frequency range, to the possibility affecting train and normally drive a vehicle be there is according to the program, therefore not consider.Wireless digital broadcasting station equipment is simple, but the diagnostic data transmission quantity peak value considering onboard system is that 50 megabyte are per hour, and the transfer rate in radio station is difficult to meet the demands.The mode of GSM message is difficult to meet this requirement equally.GPRS and take W-CDMA as the demand that the 3G of representative can meet On-Board Diagnostics (OBD) data cloud and shares in transfer rate, real-time, engineering feasibility etc.Though the transfer rate of GPRS has inferior position, substantially can meet the demand of this project, it has larger advantage in rate, and it is more extensive in the application of embedded system field, technology maturation; W-CDMA transfer rate system of system demand far away, but, and it is still immature in the application of embedded system field. on rate costlyAnd the GPRS cellular radio of local telecom operator is very ripe, even if also have covering in urban track traffic tunnel.The mode being accessed Internet by operator GPRS is selected to realize On-Board Diagnostics (OBD) real-time data sharing in the present embodiment.

Share in interface subsystem at diagnostic data cloud, in the present embodiment, select the core processing equipment of M35 type GPRS module as subsystem of QuecTel company.M35 module supports multiple GPRS/GSM frequency range, can the whole GPRS base station of compatible China Mobile and Liang Jia operator of CHINAUNICOM; Its Embedded Web service agreement stack, supports multiple Socket and IP address, and developer can call GPRS protocol stack easily by simple serial ports instruction; M35 module provides SIM card interface, by installing the SIM card of operator and paying the access that mobile communication rate can realize internet easily.In addition, phone, the SMS of M35 module also backward compatible GSM.

M35 module core circuit is as follows: M35 module 10 pin PWRKEY is controlled by core MCU module, to be started shooting/power-off operation to M35 by low and high level.12 pin STATUS pins represent the machine open/close state of M35 by its low and high level, for MCU reference.Right side S1 device is SIM card holder, the CN2 position SMA antenna of top.22 pin and 21 pin of M35 are that its serial ports communicated with MCU receives and dispatches pin, and right side is provided with plug CN100 for monitoring the steering order of MCU during hardware and software debugging.The U6 logical device of below and LED3 form LED indicating circuit, and when controlling serial ports performs the transmitting-receiving action of data, the flicker of control LED, for debugging is provided convenience.Circuit is also provided with other uncoupling electric capacity, for the stable operation of module provides support.

Described MCU module is connected with described ancillary peripheral circuit.Described ancillary peripheral circuit is mainly used in realizing the peripheral functions such as power supply, debugging interface, reset, temporal information, and the normal operation for nucleus module provides necessary support.

Described local storage subsystem and SD link and connect.Local storage subsystem is the safety guarantee of diagnostic data, the emergency function of diagnostic data cloud shared system when wireless data link is abnormal, being the key foundation of train data analysis after extreme situation, major accident, is also simultaneously that the daily data maintenance of the operation and maintenance personnel of a line is provided convenience.The storage medium kind of current main flow is a lot of, consider that the requirement of engineering to equipment volume and quality is rather harsh, requirement for memory data output is slightly low, to not consider in the present embodiment that hard disk is as storage medium, consider emphatically light, the small and exquisite and storage card alternatively object that can dock with embedded system platform.The storage card of main flow has CF card (CompactFlash), mmc card (MultiMediaCard), SD card (SecureDigitalCard), SM card (SmartMedia) several, existing as shown in table 3 to the parametric statistics of several storage card.

Based on data in table, CF card, due to its volume and qualitative inferior position, should not be selected; SM card due to its capacity too small, and its special purpose interface realizes difficulty in embedded MCU, therefore should not select; Mmc card and SD card technique similar, interface is also compatible, but SD is stuck on capacity and has a clear superiority in, and becomes the best way of realization that diagnostic data this locality stores.In February, 2010, SanDisk company releases the maximum SD card of current capacity, and capacity reaches 64GB, reads and reaches as high as 15MB/ second, can meet the demand of On-Board Diagnostics (OBD) data processing rate completely.

Table 3 main flow portable storage media performance comparison

The diagnostic data that truck-mounted computer produces is stored in SD card with the form of FAT32 file.FAT (FileAllocationTable) is the file system of a kind of practicality designed by Microsoft.FAT file system the earliest adopts the space of 16 to represent each sector configuration file, is therefore referred to as FAT16.Can only arrive 2GB because FAT16 file system disk subregion is maximum, do not support that bigdos, unit bunch capacity are greatly with shortcomings such as uniform space several wastes, FAT32 popularizes gradually and becomes widely used file system.SD card under FAT file system can be used the PC Direct Recognition of WINDOWS system, is extremely convenient to the current check work of repair and maintenance personnel.

In order to scattered diagnostic data is become file according to the format organization of FAT32, the local storage subsystem of diagnostic data employ one piece independently MCU be used as read-write and the management of SD card file, to reduce the working load of core MCU.In order to the convenience developed, selected in the present embodiment with core MCU same producer, same to kernel, with the STM32F405RGT6 of development platform as SD card managing chip.This chip equally with ARM32 position Cortex-M4 for kernel, the highest 168MHz of dominant frequency, arithmetic capability 210DMIPS.Chip adopts LQFP64 encapsulation, and low-profile, can activate two groups of spi bus interfaces and two groups of UART interface simultaneously, can meet the processing demands that subsystem manages SD card completely.

SD card is by the read-write process of SD card managing chip by SPI Interface Controller data.Meanwhile, SD card managing chip is connected with core MCU by another group SPI interface.In addition, for the ease of knowing the duty of SD card managing chip fast, the SD the core of the card sheet low and high level state of a GPIO mouth expresses free/busy state.The conveniently debugging of equipment, SD card managing chip has been drawn one group of universal asynchronous serial, and is converted to RS-232 rs 232 serial interface signal, as Debugging message interface during hardware and software debugging by SP3222 type RS-232 serial ports transceiver.Local memory card is coordinated with the slot of base plate by two groups of 20Pin plugs with between base plate, by above-mentioned signal transmission on the pin of core MCU.Plate is also provided with SD card slot and the cooperation of SD card, SP3222EEA type RS-232 bus transceiver chip is for generating RS-232 signal, and CAT706SVI type external reset chip is for tackling the unusual condition of managing chip.In addition, SD card managing chip periphery is also provided with uncoupling electric capacity, filtering circuit and the normal operation for ensureing chip, and jtag interface is used for download program, and three pieces of patch-type LED are respectively used to the instruction power supply status of plate and the reiving/transmitting state of data.。

This system can directly be docked with truck-mounted computer, by obtaining diagnostic data with the information interaction of truck-mounted computer, and realized the Real-Time Sharing of diagnostic data by radio communication according to the demand of system, possess abundant data-handling capacity to tackle the flow of diagnostic data.The diagnostic data that terminal device possesses truck-mounted computer produces quickly and reliably processes and is forwarded to the ability in data high in the clouds, to meet the needs that inline diagnosis and fault are investigated fast.Cloud sharing functionality, while consideration data traffic, fully can ensure integrality and the reliability of data, be strict controlled in misdiagnosis rate and the false alarm rate index of radiodiagnosis x.

The present invention still has numerous embodiments, all employing equivalents or equivalent transformation and all technical schemes formed, and all drops within protection scope of the present invention.

Claims (9)

1. an On-Board Diagnostics (OBD) data sharing terminal system, it is characterized in that: comprise the On-Board Diagnostics (OBD) data sharing terminal being mounted with software, described On-Board Diagnostics (OBD) data sharing terminal is connected with power supply and the debugging interface for debugging software performance by ancillary peripheral circuit, and described On-Board Diagnostics (OBD) data sharing terminal is also connected with truck-mounted computer and diagnostic data cloud and carries out two-way communication.

2. On-Board Diagnostics (OBD) terminal data shared terminal system according to claim 1, it is characterized in that: described On-Board Diagnostics (OBD) terminal data shared terminal system also includes MCU module, described MCU module is shared interface subsystem, local storage subsystem and ancillary peripheral circuit respectively and is connected with truck-mounted computer interface subsystem, cloud.

3. On-Board Diagnostics (OBD) terminal data shared terminal system according to claim 2, is characterized in that: described truck-mounted computer interface subsystem is for providing with the Ethernet interface of onboard system information interaction and being connected by FMC bus with described MCU module.

4. On-Board Diagnostics (OBD) terminal data shared terminal system according to claim 2, is characterized in that: described MCU module and described cloud are shared interface subsystem and be connected by universal asynchronous serial transceiver, and by On-Board Diagnostics (OBD) data upload to high in the clouds.

5. On-Board Diagnostics (OBD) terminal data shared terminal system according to claim 2, is characterized in that: described MCU module is connected with described ancillary peripheral circuit.

6. On-Board Diagnostics (OBD) terminal data shared terminal system according to claim 2, is characterized in that: described truck-mounted computer interface subsystem is connected with described truck-mounted computer.

7. On-Board Diagnostics (OBD) terminal data shared terminal system according to claim 6, it is characterized in that: described truck-mounted computer interface subsystem is set up TCP with described truck-mounted computer and is connected, receive the packet comprising diagnostic data information that truck-mounted computer sends, local tcp protocol stack is utilized to be resolved according to ICP/IP protocol by packet, data field content in being wrapped by TCP is stored in local FIFO memory block, and inform MCU module by the form of terminal affair, wait for the call instruction of MCU module; When MCU module access truck-mounted computer interface subsystem, the information received is returned to MCU module according to certain rule by subsystem, and empties local cache district, waits for the arrival of follow-up data.

8. On-Board Diagnostics (OBD) terminal data shared terminal system according to claim 2, is characterized in that: described cloud is shared interface subsystem and is connected with diagnostic data cloud.

9. On-Board Diagnostics (OBD) terminal data shared terminal system according to claim 2, it is characterized in that: described local storage subsystem and SD link and connect, SD card is by the read-write process of SD card managing chip by SPI Interface Controller data, and SD card management managing chip periphery is provided with uncoupling electric capacity and filtering circuit.