CN100568315C - Multi-sensor access device and data fusion method for road traffic information collection - Google Patents

Abstract

The multi-sensor access device for collecting road traffic information of the present invention includes a digital signal processor DSP, a complex programmable logic device CPLD, a signal conditioning and conversion circuit, a CAN communication controller and a network communication controller. The sensor signal collected by the road traffic information is connected to the CPLD through the current-voltage conversion circuit, the voltage-frequency conversion circuit, and the level conversion circuit. CPLD expands the number of DSP signal access and has signal processing functions. The invention also provides a method for multi-sensor data fusion processing. The advantages of the present invention are: the field bus level communication is realized through the CAN communication controller, the large-capacity data communication with the computer of the traffic control center is realized through the network communication controller, the sensors used for collecting the existing road traffic information can be connected, and the sensor wiring and network are simplified. The transmission requirements have achieved the effect of integration of traffic information detection devices and large-scale detection.

Description

Multi-sensor access device and data fusion method for road traffic information collection

technical field

The invention relates to the application of network technology, in particular to a multi-sensor access device for collecting road traffic information and a data fusion method thereof.

Background technique

At present, the road traffic system of large and medium-sized cities in my country has deployed a large number of traffic information sensors, such as coil, video, microwave, infrared, ultrasonic, temperature and humidity sensors, which have been initially satisfied.

However, the current sensor deployment methods are independent of each other and belong to different systems. They cannot directly interact with data and provide comprehensive three-dimensional traffic information. The sensors have limited functions and cannot directly obtain interval traffic parameters and introduce weather information into traffic signal control. Since various applications in the traffic system require multi-source traffic information, the problems with this sensor deployment method are:

(1) Occupying huge network resources, each sensor must be equipped with a separate data transmission line, and the wiring work has become the main work of sensor deployment;

(2) Existing sensor deployment methods generate a large amount of heterogeneous data, but existing sensors lack online processing capabilities, and these data need to be uploaded to the traffic control center through the data transmission network, so the requirements for data transmission network resources are high;

(3) The mass data generated by the existing sensor deployment method has extremely high requirements on the processing capacity of the background system and leads to an increasing integration complexity for global comprehensive applications;

(4) Existing sensors lack online processing capabilities, and the traffic status information required by various applications of intelligent transportation systems cannot be obtained online, in real time, and accurately.

The key to this problem is that there is no comprehensive sensor access and online fusion device, so that each traffic sensor can be independently deployed and transmitted to the traffic management center through its own communication network. The development of my country's intelligent transportation system urgently requires changing the existing way of collecting traffic status information.

Contents of the invention

The purpose of the present invention is to overcome the defects of the existing technology, and provide a dynamic reconfigurable access device and adaptive data processing and fusion method for multi-type sensors for traffic information collection in the same device, thereby simplifying sensor wiring , Reduce the pressure of network transmission, realize the integration of traffic information system, multi-sensor access device for road traffic information collection of large-scale detection, and provide a method for multi-source sensor data fusion processing at the same time.

In order to achieve the above object, the multi-sensor access device for road traffic information collection provided by the present invention includes a digital signal processor DSP, a network communication controller connected to the digital signal processor DSP, a CAN communication controller and/or several Signal conditioning and conversion circuit, the network communication controller is used to communicate with the communication network under the control of the digital signal processor DSP, the CAN communication controller is used to communicate with the device with CAN interface, the signal conditioning and The conversion circuit is used to collect the sensor data of the analog output sensor, the switch output sensor and the pulse sequence output into the digital signal processor DSP;

Described network communication controller is made of Ethernet controller, isolation transformer, RJ45 interface, and described network communication controller uses NTCIP agreement to carry out network communication; Described CAN communication controller is controlled by eCAN control module, optocoupler isolator, CAN The CAN communication controller uses the CAN protocol to perform data communication with a device with a CAN interface or to collect data with a sensor with a CAN interface;

Described digital signal processor DSP adopts the chip that model is TMS320F2812;

It also includes a complex programmable logic device CPLD connected with the digital signal processor DSP, and the complex programmable logic device CPLD includes a read-write control module, a sensor channel selection module, a sensor signal processing module, a peripheral equipment control module, a matrix Keyboard control module, LCD display control module, in which:

The read-write control module is used for the read-write sequence control of the address bus, data bus and control bus used for data exchange between the complex programmable logic device CPLD and the digital signal processor DSP, according to the data lines, Address lines and read-write and chip select control signals complete the data transmission between the CPLD and the DSP;

The sensor channel selection module is used to switch channels for dynamic reconfiguration of sensors according to the instructions of the digital signal processor DSP;

The sensor signal processing module is configured to perform adaptive data processing on the sensor input data;

The peripheral device control module is used to expand address decoding and chip selection control of peripheral devices;

The matrix keyboard control module is used to judge the key value of the button and input the key value to the digital signal processor DSP through the data line;

The LCD display control module is used for timing control of the LCD liquid crystal display, and transmits data content to be displayed to the LCD display.

The multi-sensor access device for road traffic information collection of the present invention, wherein the sensor signal processing module included in the CPLD includes a timer, a counter, a result register and an interrupt control register, wherein:

The timer is used to generate an adaptive timing cycle using an external clock signal as a time reference;

said counter for recording the number of incoming pulses of the sensor during said adaptive timing period;

The result register is used to record the counting result of the counter;

The interrupt control register is used to store the interrupt type that sends the interrupt.

The multi-sensor access device for road traffic information collection of the present invention, wherein the CPLD adopts a chip with a model number of EPM1270T144C5N, and the sensor channel selection module included in the CPLD includes a channel selection control register and a multiplexer, wherein:

The channel selection control register is used to store the data of the reconfigurable access mode sent from the digital signal processor DSP;

The multiplexer is used to determine the on-off of each channel according to the data in the channel selection control register.

The multi-sensor access device for collecting road traffic information of the present invention, wherein the signal of the current output sensor is input into the CPLD through the current-voltage conversion circuit and the voltage-frequency conversion circuit, and the signal of the voltage output sensor is input into the CPLD through the voltage-frequency conversion circuit , the signal of the switching value output sensor is input into the CPLD through the level conversion circuit; the CPLD is also connected with a keyboard circuit and a liquid crystal display circuit.

The multi-sensor access device for road traffic information collection of the present invention, the network communication controller is composed of an Ethernet controller, an isolation transformer, and an RJ45 interface, and the network communication controller uses the NTCIP protocol for network communication; the digital signal processing The device DSP also includes an eCAN control module, the CAN communication controller is composed of an eCAN control module, an optocoupler isolator, and a CAN controller interface, and the CAN communication controller uses the CAN protocol to perform data communication with a device with a CAN interface Or carry out data acquisition with sensors with CAN interface.

In order to achieve the above object, the present invention provides a data transmission method for a multi-sensor access device, in which the sensor input signal is connected to the digital signal processor via CLPD and/or CAN communication controller and/or signal conditioning circuit DSP, and the processed data network is transmitted to the traffic management center computer by the network communication controller, and the method performs the following steps:

Step 1, device initialization, including DSP initialization, network communication controller initialization, CAN controller initialization, and peripheral chip initialization;

Step 2, the DSP receives the command sent by the traffic control center computer through the network communication controller, analyzes the command, whether to perform sensor data collection, if yes, then proceeds to the next step; otherwise, sends an inquiry message to the traffic control center computer or wait;

Step 3, if the command of the traffic management center computer is to instruct the CAN bus to carry out data transmission, then start the CAN communication controller to carry out data transmission; if it is to carry out direct data acquisition, then start the complex programmable logic device CPLD and the signal conditioning circuit to collect data;

Step 4, DSP receives and temporarily stores the data processed by CPLD, DSP receives and temporarily stores the data of CAN bus, DSP temporarily stores the data directly input to DSP, checks whether the memory capacity is full, if so, clears the memory, and transfers to Step 6; otherwise continue to operate;

Step 5, performing multi-source data fusion processing, and storing fusion results;

Step 6, according to the command of the computer of the traffic management center, transmit data to the computer of the traffic management center through the network communication controller;

Step 7, return to step 2, and wait for the next data collection process.

Data fusion method of the present invention, wherein said sensor is a coil sensor, and the steps of said digital signal processor DSP data processing are as follows:

Step 1: Read the sampling time value, sampling location, period value k, and sampling period T _i ;

Step 2: Read in the flow data Q _i i=1,...,n detected by the coil sensor at the n corresponding moment in the k-th period, and calculate the average flow Q _k in the k-th period;

Step 4: Calculate the time occupancy rate O _i i=1,...,n, and calculate the average time occupancy rate O _k in the kth period;

Step 5: Store the average flow rate, average occupancy rate, collection location, and collection period of the k-th period;

Step 6: k=k+1, go to step 1.

In the data fusion method of the present invention, wherein the sensor is a coil sensor and a geomagnetic sensor with a CAN interface, the digital signal processor DSP performs multi-source data fusion processing, and the steps are as follows:

Step 1: Initialize road section parameters, set flow rate μ, read period value k, period T, sampling period T _i , green light time g _k , tolerance δ;

Step 2: Read the average flow and occupancy data for the kth period from the coil data

(1) read in the flow data detected by the flow data detected by the coil sensor at the n corresponding moments of the k period;

Q _i i=1,...,n; calculate the average flow Q _k of the kth period;

(2) Calculate the time occupancy rate O _i i=1,...,n; calculate the average time occupancy rate O _k of the kth period;

(3) Store the average flow rate, average occupancy rate, and collection period of the kth period;

Step 3: Estimate the queuing time of the road section from the coil data, the method is:

(1) read the coil flow data Q _k and occupancy rate data O _k of the kth period of time from the coil sensor;

(2) Calculate the average vehicle entry rate λ _k and exit rate μ _k in the k-th period;

(3) Estimate the queuing time using the segmented time homogeneous Markov queuing model, and calculate the queuing time as T _q (k);

Step 4: Get the average queue length from the geomagnetic sensor with CAN interface, the method is

(1) At the nth corresponding moment in the k period, read the m geomagnetic sensors with the CAN interface from the CAN interface in the i-th sampling period to collect the vehicle data D ₁ (i), D ₂ ( i), ..., D _m (i), wherein i=1, 2, ..., n; it is stipulated that the numbering of the geomagnetic sensor near the intersection is m, and the numbering of the farthest geomagnetic sensor from the intersection is 1;

(2) Calculate the queue length of the i-th sampling period, start from the m-th data D _m (i), search in the direction of D ₁ (i), and search for the first data of D _j (i)=0, then The queue length is the length l(i) from the jth geomagnetic sensor to the intersection;

(3) calculate the average queue length L _k of the k period;

Step 5: Obtain the flow distribution on the road section from the coil sensor and the geomagnetic sensor with CAN interface:

(1) In the kth period, the i-th sampling period reads the flow data from the coil sensor, where i=1, 2, ..., n, and calculates its flow mean value and variance,

The mean value of flow in the k-th period is Q _k ,

The flow standard deviation S _Q (k) of the k-th period,

In the kth period, the i-th sampling period reads vehicle data from m geomagnetic sensors, where i=1, 2, ..., n, and calculates the mean value and variance of the flow detected by each geomagnetic sensor;

(2) The flow distribution of the entire road section is composed of coil sensors and m geomagnetic sensors

The distribution of traffic flow in the k-th period [Q _k , D ₁ ^k ,..., D _m ^k ]

The distribution of traffic standard deviation in the k-th period of time $[S_Q,S_{{\mathrm{D.}}_1},...,S_{{\mathrm{D.}}_m}],$

Step 6, if the calculation is not over then k=k+1, go to step 1; otherwise go to step 7;

Step 7, end and return.

The data fusion method of the present invention, wherein said CAN communication controller performs the following steps:

A. Sending process

Step 1, initialize the DSP and its eCAN module, including:

(1) Enable CAN module clock,

(2) Set CANTX and CANRX as CAN communication pins,

(3) Configuration bit time configuration register CANBTC,

(4) Configure the receiving mask register CANGAM,

(5) configure the main control register CANMC,

(6) clear all bits of the message control register MSGCTRLn;

Step 2 Configure the sending mailbox, including:

(1) Clear the corresponding bit in the sending request setting register CANTRS;

(2) Clear the corresponding bit in the mailbox enabling register CANME, and shield the mailbox;

(3) load the message identifier register MSGID of the mailbox;

(4) Write the data length to the data length code DLC area of the message control area register MSGCTRL;

(5) Set the corresponding bit in the mailbox enabling register CANME to enable the mailbox.

Step 3 Send a message, including:

(1) Write a message to the data area of the corresponding sending mailbox;

(2) corresponding flag bit is set to start message sending in sending request register CANTRS;

(3) wait to send the corresponding mailbox in the response register CANTA to send the response flag position setting;

(4) After successful transmission or abort transmission, the module will reset the corresponding value of the transmission request setting register CANTRS;

Step 4: After sending, return to the calling place;

B. Receiving process

Step 1 initializes the DSP and its eCAN module, including:

(1) Enable CAN module clock,

(2) Set CANTX and CANRX as CAN communication pins,

(3) Configuration bit time configuration register CANBTC,

(4) Configure the receiving mask register CANGAM,

(5) configure the main control register CANMC;

(6) clear all bits of the message control register MSGCTRLn;

Step 2 Configure the receiving mailbox, including:

(1) Clear the corresponding bit in the mailbox enabling register CANME, and shield the mailbox;

(2) Write the identifier to the corresponding message flag register MSGID;

(3) If the receive mask register enable bit AME of the message flag register MSGID is set to 1, the corresponding receive mask must be configured;

(4) Set the mailbox direction register CANMD, and configure the corresponding mailbox to receive the mailbox;

(5) If the data in the mailbox is protected, it is necessary to configure the coverage control register CANOPC;

(6) Set the corresponding bit in the mailbox enabling register CANME to enable the mailbox;

Step 3 Receive the message

Query whether the corresponding bit RMPx in the receiving message pending register CANRMP corresponding to the corresponding mailbox is set to 1, if it is, it indicates that the mailbox has completed receiving data, otherwise the reception has not been completed, and continue to inquire;

Step 4: After receiving, return to the calling place.

In the data fusion method of the present invention, the network communication controller performs the following steps:

Step 1 initializes the DSP and Ethernet controller;

Step 2 detects whether there is data from the network, if there is, then step 3, otherwise step 6;

Step 3 judges whether it is the UDP User Datagram Protocol, otherwise step 4; if then proceeds to the UDP processing program; proceeds to step 5 after completion;

Step 4 judges whether it is the TCP transmission control protocol, otherwise step 6; if so, the program proceeds to the TCP processing program, and proceeds to step 5 after completion;

Step 5 sends the processed data into the DSP for processing, and proceeds to step 2 after completion;

Step 6 Whether the DSP has data to be sent, if so, go to step 7, otherwise go to step 2;

Step 7 If there is and UDP protocol is selected, then process according to the UDP protocol, and send the data to the traffic control center computer; then go to step 2, otherwise go to step 8;

Whether step 8 is the TCP protocol, if so, process according to the TCP protocol, send the data to the computer of the traffic control center, and turn to step 2 after sending, otherwise turn to step 2.

The advantages of the multi-sensor access device for road traffic information collection and its data fusion method of the present invention are:

1. It has the function of accessing multi-type sensors and multi-source data fusion: the access device can access sensors covering analog output, switch output and pulse data output commonly used in road traffic information collection, such as coil, microwave, ultrasonic, infrared , video sensors, etc., avoiding the problem that each type of sensor currently used needs to independently deploy related transmission and processing systems. The multi-source data fusion function of the device can meet the needs of the intelligent transportation system for comprehensive three-dimensional traffic information, avoid the transmission of original massive data, and reduce the pressure of background system processing.

2. It has the functions of bottom field bus communication and upper layer data network communication: the system formed by this device has good scalability, greatly simplifies the sensor wiring and the requirements for network transmission. This device conforms to the existing communication specifications and can be directly connected to the existing In the system, the modification cost is very little.

The following will be described in detail with reference to the accompanying drawings in conjunction with the embodiments, in order to gain a deeper understanding of the purpose, features and advantages of the present invention.

Description of drawings

Fig. 1 is the block diagram of the multi-sensor access device of road traffic information collection of the present invention;

Fig. 2 is the block diagram of CPLD structure in the multi-sensor access device of road traffic information collection of the present invention;

Fig. 3 is a CAN communication controller block diagram in the multi-sensor access device of road traffic information collection of the present invention;

Fig. 4 is a block diagram of the network communication controller in the multi-sensor access device for road traffic information collection of the present invention;

Fig. 5 is the circuit principle diagram of the CAN communication controller in the multi-sensor access device of road traffic information collection of the present invention;

Fig. 6 is the circuit principle of the current-voltage conversion circuit in the multi-sensor access device for road traffic information collection of the present invention;

Fig. 7 is a schematic diagram of the voltage regulation circuit in the multi-sensor access device for road traffic information collection of the present invention;

Fig. 8 is a schematic diagram of a level conversion circuit in a multi-sensor access device for collecting road traffic information according to the present invention;

Fig. 9 is a schematic diagram of a voltage-frequency conversion circuit in a multi-sensor access device for collecting road traffic information according to the present invention;

Fig. 10 is a schematic circuit diagram of the network communication controller in the multi-sensor access device for collecting road traffic information of the present invention;

Fig. 11 is the circuit principle diagram of DSP in the multi-sensor access device of road traffic information collection of the present invention;

Fig. 12 is the circuit principle diagram of CPLD in the multi-sensor access device of road traffic information collection of the present invention;

Fig. 13 is a data transmission flow chart of the multi-sensor access device for road traffic information collection of the present invention;

Fig. 14 is a flow chart of data reception by the CAN communication controller in the multi-sensor access device for road traffic information collection of the present invention;

Fig. 15 is a flow chart of data transmission by the CAN communication controller in the multi-sensor access device for road traffic information collection of the present invention;

Fig. 16 is a flow chart of data transmission by the network communication controller in the multi-sensor access device for collecting road traffic information according to the present invention.

Detailed ways

The technical scheme adopted by the present invention to solve its technical problems is: take digital signal processor (Digital Signal Processor, DSP) and programmable logic device CPLD (Complex Programmable Logic Device) as the core, also includes CAN (Controller Area Network, CAN) Communication controller, network communication controller and signal conditioning and conversion circuit.

The multi-sensor access device for road traffic information collection of the present invention can be connected to multiple types of heterogeneous sensors, such as analog sensors whose output is current signals, analog sensors whose outputs are voltage signals, switching sensors whose outputs are level signals, The output is a digital sensor with a pulse sequence; at the same time, the device also has a CAN communication interface, which can be connected to sensor data transmitted through the field bus and connected to a sensor with a CAN interface.

The multi-sensor access device of the present invention utilizes the processing capability of the DSP and can embed a data fusion algorithm to realize online fusion of multi-source heterogeneous sensors.

The multi-sensor access device of the present invention will be described in detail below with embodiments.

The technical solution adopted by the present invention to solve the technical problem is: referring to Fig. 1, the existing sensors are connected to CPLD and DSP, and fusion processing is performed on them, and the processing results are transmitted to the traffic management center computer through the network communication controller. Traffic information collection sensors such as sensors with a CAN interface will input data into the DSP through the CAN communication controller of the device; sensors without CAN interfaces such as coils, video, microwave, infrared, ultrasonic, temperature and humidity, etc. Signal conditioning and conversion circuits enter CPLD or DSP.

Among them, the DSP part: see Figure 11, the DSP receives instructions from the computer of the traffic control center, performs fusion processing on the connected sensor information, and transmits the processed data to the computer of the traffic control center. DSP uses the chip model as TMS320F2812.

CPLD part: see Figure 12, the chip model used by CPLD is EPM1270T144C5N. The CPLD part has 5 functional modules, which are read-write control module, sensor channel selection module, sensor signal processing module, peripheral equipment control module, matrix keyboard control module, and LCD display control module.

●The read-write control module is used for the read-write sequence control of address bus, data bus and control bus during data exchange between CPLD and DSP. The sensor channel selection module performs channel switching for dynamic reconstruction of the sensor according to the instructions of the DSP. The so-called channel switching of dynamic reconstruction refers to the method of dynamically connecting or cutting off the channel of the sensor connected to the CPLD through the CPLD under the command of the DSP under the precondition that all road traffic information collection sensors have been connected to the device.

●The sensor signal processing module is used for adaptive data processing on the sensor input data. The so-called adaptive data processing is to dynamically change the counting period according to the counting result of the input signal of the sensor, which has met the requirement of counting precision.

●Peripheral equipment control module, used to expand the address decoding and chip selection control of peripheral equipment.

●The matrix keyboard control module is used to judge the key value of the key and input the key value to the DSP through the data line.

●LCD display control module, used for LCD timing control, and transmits the data content to be displayed to the LCD display.

When connecting to the existing sensor, the current output sensor connects the signal to the CPLD through the current-voltage conversion circuit and the voltage-frequency conversion circuit; the voltage output sensor connects the signal to the CPLD through the voltage-frequency conversion circuit; The conversion circuit connects the signal to the CPLD, and the output terminal of the CPLD is connected to the DSP; the CPLD is also connected to a keyboard circuit and a liquid crystal display circuit, which are responsible for keyboard reading and liquid crystal display control. The connection between CPLD part and DSP is: data bus D8-D15, address bus A0-A18, control lines XZCS2, XWE, XRD.

CAN communication controller: used to input the data of sensors with CAN interface into network nodes, or communicate with devices with CAN interface. Referring to Figure 3 and Figure 5, the CAN communication controller adopts the chip of model TMS320F2812, which is composed of eCAN control module in DSP, optocoupler isolator, and CAN controller interface. Several optocouplers are connected between the eCAN module and the CAN controller interface. The optocoupler isolator uses a chip of model 6N137. The bus driver adopts the chip of model PAC82C250. The connection between the CAN communication controller and the DSP is: the signal entering the DSP is CANRXA, and the signal sent from the DSP is CANTXA.

Network communication controller: used for data and instruction interaction with the traffic control center computer, see Figure 4 and Figure 10, including Ethernet controller, isolation transformer and RJ45 interface. The Ethernet controller uses a chip model of CS8900A. The isolation transformer model is HR601627. The connection with DSP is: data bus D0-D15, address line CSA1-3, control line xzcs0and1, XRD, XWE. The network communication controller uses the NTCIP bus protocol for network communication.

Signal conditioning and conversion circuit: see Figure 6, the current output sensor signal conditioning and conversion circuit includes a current-voltage conversion circuit and a voltage-frequency conversion circuit. Referring to Fig. 7, the voltage output sensor signal conditioning and conversion circuit includes a voltage frequency conversion circuit. Referring to Fig. 8, the sensor signal conditioning and conversion circuit for switching output includes an optocoupler and a level conversion circuit.

The multi-sensor access device uses DSP's own AD converter and capture unit to directly access sensor signals, and the CAN communication controller composed of DSP's eCAN module can receive data from devices or sensors with CAN interfaces. Due to the limited access of DSP itself, and the fusion algorithm, communication control and other tasks to be completed take up a lot of its resources, the CPLD is extended to access more sensors and perform data processing. In this way, the core structure of DSP+CPLD is used to realize multi-type , multi-channel, multi-combination flexible and controllable sensor signal access scheme, which effectively solves the problems of many types of sensors used in urban road traffic, large data volume, and wide coverage area.

There are three main access methods for this device:

(1) use the peripheral resources of the DSP device to complete the access;

(2) Use the CAN interface to complete the access to the sensor with CAN communication function;

(3) Use CPLD for access expansion, and complete part of data processing by CPLD to reduce the pressure on DSP.

In addition, on the one hand, the device can be manually controlled through the keyboard, and on the other hand, it can also realize remote monitoring and command delivery to the device through the data network.

The method for fusion processing of multi-type heterogeneous sensor information of the present invention will be described in detail below.

Referring to Fig. 13, in the embodiment of this method, the sensor input signal collected by the network is connected to the digital signal processor DSP through CLPD and/or CAN communication controller and/or signal conditioning circuit, and is controlled by network communication The processed data network is transmitted to the traffic management center computer by the controller, and the steps of the method are:

Step 1, device initialization, including DSP initialization, network communication controller initialization, CAN controller initialization, and peripheral chip initialization;

Step 2, the DSP receives the command sent by the traffic control center computer through the network communication controller, analyzes the command, whether to perform sensor data collection, if yes, then proceeds to the next step; otherwise, sends an inquiry message to the traffic control center computer or wait;

Step 3, if the command of the traffic management center computer is to instruct the CAN bus to carry out data transmission, then start the CAN communication controller to carry out data transmission; if it is to carry out direct data acquisition, then start the complex programmable logic device CPLD and the signal conditioning circuit to collect data;

Step 4, DSP receives and temporarily stores the data processed by CPLD, DSP receives and temporarily stores the data of CAN bus, DSP temporarily stores the data directly input to DSP, checks whether the memory capacity is full, if so, clears the memory, and transfers to Step 6; otherwise continue to operate;

Step 5, performing multi-source data fusion processing, and storing fusion results;

Step 6, according to the command of the computer of the traffic management center, transmit data to the computer of the traffic management center through the network communication controller;

Step 7, return to step 2, and wait for the next data collection process.

Wherein, if the sensor is a coil sensor, the steps of the digital signal processor DSP data processing are as follows:

Step 1: Read the sampling time value, sampling location, period value k, and sampling period T _i ;

Step 2: Read in the flow data Q _i i=1,...,n detected by the coil sensor at the n corresponding moment in the k-th period, and calculate the average flow Q _k in the k-th period;

Step 4: Calculate the time occupancy rate O _i i=1,...,n, and calculate the average time occupancy rate O _k in the kth period;

Step 5: Store the average flow rate, average occupancy rate, collection location, and collection period of the k-th period;

Step 6: k=k+1, go to step 1.

If the sensor is a coil sensor and a geomagnetic sensor with a CAN interface, the digital signal processor DSP performs multi-source data fusion processing, and the steps are as follows:

Step 1: Initialize road section parameters, set flow rate μ, read period value k, period T, sampling period T _i , green light time g _k , tolerance δ;

Step 2: Read the average flow and occupancy data for the kth period from the coil data

(1) read in the flow data detected by the flow data detected by the coil sensor at the n corresponding moments of the k period;

Q _i i=1,...,n; calculate the average flow Q _k of the kth period;

(2) Calculate the time occupancy rate O _i i=1,...,n; calculate the average time occupancy rate O _k of the kth period;

(3) Store the average flow rate, average occupancy rate, and collection period of the kth period;

Step 3: Estimate the queuing time of the road section from the coil data, the method is:

(1) read the coil flow data Q _k and occupancy rate data O _k of the kth period of time from the coil sensor;

(2) Calculate the average vehicle entry rate λ _k and exit rate μ _k in the k-th period;

(3) Estimate the queuing time using the segmented time homogeneous Markov queuing model, and calculate the queuing time as T _q (k);

Step 4: Get the average queue length from the geomagnetic sensor with CAN interface, the method is

(1) At the nth corresponding moment in the k period, read the m geomagnetic sensors with the CAN interface from the CAN interface in the i-th sampling period to collect the vehicle data D ₁ (i), D ₂ ( i), ..., D _m (i), wherein i=1, 2, ..., n; it is stipulated that the numbering of the geomagnetic sensor near the intersection is m, and the numbering of the farthest geomagnetic sensor from the intersection is 1;

(2) Calculate the queue length of the i-th sampling period, start from the m-th data D _m (i), search in the direction of D ₁ (i), and search for the first data of D _j (i)=0, then The queue length is the length l(i) from the jth geomagnetic sensor to the intersection;

(3) calculate the average queue length L _k of the k period;

Step 5: Obtain the flow distribution on the road section from the coil sensor and the geomagnetic sensor with CAN interface:

(1) In the kth period, the i-th sampling period reads the flow data from the coil sensor, where i=1, 2, ..., n, and calculates its flow mean value and variance,

The mean value of flow in the k-th period is Q _k ,

The flow standard deviation S _Q (k) of the k-th period,

In the kth period, the i-th sampling period reads vehicle data from m geomagnetic sensors, where i=1, 2, ..., n, and calculates the mean value and variance of the flow detected by each geomagnetic sensor;

(2) The flow distribution of the entire road section is composed of coil sensors and m geomagnetic sensors

The distribution of traffic flow in the k-th period [Q _k , D ₁ ^k ,..., D _m ^k ]

The distribution of traffic standard deviation in the k-th period of time $[S_Q,S_{{\mathrm{D.}}_1},...,S_{{\mathrm{D.}}_m}],$

Step 6, if the calculation is not over then k=k+1, go to step 1; otherwise go to step 7;

Step 7, end and return.

Referring to Figure 14 and Figure 15, the method for data transmission by the CAN communication controller is:

A. Sending process

Step 1, initialize the DSP and its eCAN module, including:

(1) Enable CAN module clock,

(2) Set CANTX and CANRX as CAN communication pins,

(3) Configuration bit time configuration register CANBTC,

(4) Configure the receiving mask register CANGAM,

(5) configure the main control register CANMC,

(6) clear all bits of the message control register MSGCTRLn;

Step 2 Configure the sending mailbox, including:

(1) Clear the corresponding bit in the sending request setting register CANTRS;

(2) Clear the corresponding bit in the mailbox enabling register CANME, and shield the mailbox;

(3) load the message identifier register MSGID of the mailbox;

(4) Write the data length to the data length code DLC area of the message control area register MSGCTRL;

(5) Set the corresponding bit in the mailbox enabling register CANME to enable the mailbox.

Step 3 Send a message, including:

(1) Write a message to the data area of the corresponding sending mailbox;

(2) corresponding flag bit is set to start message sending in sending request register CANTRS;

(3) wait to send the corresponding mailbox in the response register CANTA to send the response flag position setting;

(4) After successful transmission or abort transmission, the module will reset the corresponding value of the transmission request setting register CANTRS;

Step 4: After sending, return to the calling place;

B. Receiving process

Step 1 initializes the DSP and its eCAN module, including:

(1) Enable CAN module clock,

(2) Set CANTX and CANRX as CAN communication pins,

(3) Configuration bit time configuration register CANBTC,

(4) Configure the receiving mask register CANGAM,

(5) configure the main control register CANMC;

(6) clear all bits of the message control register MSGCTRLn;

Step 2 Configure the receiving mailbox, including:

(1) Clear the corresponding bit in the mailbox enabling register CANME, and shield the mailbox;

(2) Write the identifier to the corresponding message flag register MSGID;

(3) If the receive mask register enable bit AME of the message flag register MSGID is set to 1, the corresponding receive mask must be configured;

(4) Set the mailbox direction register CANMD, and configure the corresponding mailbox to receive the mailbox;

(5) If the data in the mailbox is protected, it is necessary to configure the coverage control register CANOPC;

(6) Set the corresponding bit in the mailbox enabling register CANME to enable the mailbox;

Step 3 Receive the message

Query whether the corresponding bit RMPx in the receiving message pending register CANRMP corresponding to the corresponding mailbox is set to 1, if it is, it indicates that the mailbox has completed receiving data, otherwise the reception has not been completed, and continue to inquire;

Step 4: After receiving, return to the calling place.

Referring to Figure 16, the network communication controller performs the following steps for data transmission:

Step 1 initializes the DSP and Ethernet controller;

Step 2 detects whether there is data from the network, if there is, then step 3, otherwise step 6;

Step 3 judges whether it is the UDP User Datagram Protocol, otherwise step 4; if then proceeds to the UDP processing program; proceeds to step 5 after completion;

Step 4 judges whether it is the TCP transmission control protocol, otherwise step 6; if so, the program proceeds to the TCP processing program, and proceeds to step 5 after completion;

Step 5 sends the processed data into the DSP for processing, and proceeds to step 2 after completion;

Step 6 Whether the DSP has data to be sent, if so, go to step 7, otherwise go to step 2;

Step 7 If there is and UDP protocol is selected, then process according to the UDP protocol, and send the data to the traffic control center computer; then go to step 2, otherwise go to step 8;

The multi-sensor access device and the data processing method thereof of the present invention have the following technical effects:

1. It has the function of connecting multiple types of sensors: covering sensors such as coils, microwaves, ultrasonics, infrared, video sensors, etc., which are commonly used in road traffic information collection at present The use of one type of sensor requires independent deployment of the associated transmission and processing system issues.

2. It has the function of online multi-source data fusion: it can meet the needs of intelligent transportation systems for comprehensive three-dimensional traffic information, avoid the transmission of original massive data, and reduce the pressure of background system processing.

3. It has the functions of bottom field bus communication and upper layer data network communication: the system formed by this device has good scalability, greatly simplifies the sensor wiring and the requirements for network transmission. This device conforms to the existing communication specifications and can be directly connected to the existing In the system, the transformation cost is very little.

At present, there is no such product on the market, and this product can improve and promote the access, use and deployment of traffic information collection sensors.

The above-mentioned embodiments are only descriptions of preferred implementations of the present invention, and are not intended to limit the scope of the present invention. On the premise of not departing from the spirit of the present invention, ordinary engineers and technicians in the field have made technical solutions of the present invention. Various modifications and improvements should fall within the scope of protection determined by the claims of the present invention.

Claims (9)

1. the multi-sensor access device of an acquisition of road traffic information, comprise digital signal processor DSP, the network communication controller that links to each other with described digital signal processor DSP, CAN communication controller and/or some signal conditions and translation circuit, described network communication controller is used for carrying out communication with communication network under described digital signal processor DSP control, described CAN communication controller is used for carrying out communication with the device with CAN interface, described signal condition and translation circuit are used for the sensor of analog quantity output, the sensor data acquisition of the sensor of switching value output and pulse train output is gone into described digital signal processor DSP, it is characterized in that:

Described network communication controller is made of ethernet controller, isolating transformer, RJ45 interface, described network communication controller uses the NTCIP agreement to carry out network communication: described CAN communication controller is by eCAN control module, optical coupling isolator, the CAN control unit interface constitutes, and described CAN communication controller uses the CAN agreement to carry out carrying out data communication or carrying out data acquisition with the sensor of being with the CAN interface with the device of band CAN interface;

It is the chip of TMS320F2812 that described digital signal processor DSP adopts model;

Also comprise a complex programmable logic device (CPLD) that is connected with described digital signal processor DSP, described complex programmable logic device (CPLD) comprises read-write control module, sensor passage selection module, sensor signal processing module, peripheral unit control module, matrix keyboard control module, LCD display control module, wherein:

Described read-write control module, the read-write sequence of used address bus, data bus and control bus control when being used for exchanges data between described complex programmable logic device (CPLD) and the described digital signal processor DSP is finished data transmission between described CPLD and the DSP according to data line, address wire and read-write and sheet selected control system signal;

Described sensor passage is selected module, is used for carrying out according to the instruction of described digital signal processor DSP the passage switching of sensor dynamic restructuring;

Described sensor signal processing module is used for that described sensor input data are carried out self-adapting data and handles;

Described peripheral unit control module is used to expand the address decoding and the sheet selected control system of peripherals;

Described matrix keyboard control module is used to judge the key assignments of button and described key assignments is inputed to described digital signal processor DSP by data line;

Described LCD display control module is used for the sequential control of LCD LCD, and transmits data content to be shown to LCD display.

2. multi-sensor access device according to claim 1, it is characterized in that: it is the chip of EPM1270T144C5N that wherein said CPLD adopts model, the sensor signal processing module that described CPLD comprises comprises timer, counter, result register and interrupt control register, wherein:

Described timer is used for producing the self-adaptation timing cycle with external timing signal as time reference;

Described counter is used for the number of pulses that the record sensor is imported in described self-adaptation timing cycle;

Described result register is used to write down the count results of described counter;

Described interrupt control register is used to store the interrupt type that sends interruption.

3. multi-sensor access device according to claim 2 is characterized in that: the sensor passage that wherein said CPLD comprises selects module to comprise channel selecting control register and MUX, wherein:

Described channel selecting control register is used to store the data of the restructural access way of sending from described digital signal processor DSP;

Described MUX is used for determining according to the data of described channel selecting control register the break-make on each road.

4. multi-sensor access device according to claim 3, it is characterized in that: wherein the signal of electric current output transducer is imported described CPLD through current-voltage conversion circuit, voltage-frequency conversion circuit, the signal of voltage output transducer is imported described CPLD through the voltage-frequency conversion circuit with signal, and the signal of switching value output transducer is imported described CPLD through level-conversion circuit; Described CPLD also is connected with keyboard circuit and liquid crystal display circuit.

5. adopt the data transmission method of the arbitrary described multi-sensor access device of claim 1-4, this method inserts described digital signal processor DSP with sensor input signal through CLPD and/or CAN communication controller and/or signal conditioning circuit, and the data network of handling is transferred to the traffic control central computer by network communication controller, it is characterized in that: this method is carried out following steps:

Step 1, the device initialization comprises DSP initialization, network communication controller initialization, the initialization of CAN controller, peripheral chip initialization;

Step 2, described DSP receives the order that the traffic control central computer sends by described network communication controller, resolves this order, whether carries out sensor data acquisition, if then change next step over to; Otherwise, send query messages or wait to the traffic control central computer;

Step 3, bus is carried out data transmission if the order of traffic control central computer is indication CAN, then starts described CAN communication controller and carries out data transmission; If carry out direct data capture, then start described complex programmable logic device (CPLD) and described signal conditioning circuit image data;

Step 4, DSP receives and keeps in the data after CPLD handles, the temporary data that are directly inputted into DSP of data, DSP that DSP received and kept in the CAN bus, checks whether memory span is full, if then clear up internal memory, and changes step 6 over to; Otherwise continue operation;

Step 5 is carried out the multi-source data fusion treatment, and the storage fusion results;

Step 6 is carried out data transmission by described network communication controller to the traffic control central computer according to the order of traffic control central computer;

Step 7 turns back to step 2, waits for data acquisition process next time.

6. method according to claim 5 is characterized in that: wherein said sensor is a coil pickoff, and the step of described digital signal processor DSP data processing is as follows:

Step 1: read sampling time value, sampling position, the time segment value k, sampling period T _i

Step 2: n the corresponding moment in the k period read in the data on flows Q that coil pickoff detects _iI=1 ..., n calculates the average discharge Q of k period _k

Step 4: computing time occupation rate O _iI=1 ..., n calculates occupation rate O averaging time of k period _k

Step 5: store k period average discharge, average occupancy, collecting location, collection period;

Step 6:k=k+1 changes step 1 over to.

7. method according to claim 5 is characterized in that: wherein said sensor is the geomagnetic sensor of coil pickoff and band CAN interface, and described digital signal processor DSP is carried out the multi-source data fusion treatment, and step is as follows:

Step 1: initialization highway section parameter is provided with flow rate μ, segment value k, period T, sampling period T when reading _i, green time g _k, tolerance δ;

Step 2: from average discharge and the occupation rate data of coil data read k period

(1) reads in the data on flows that data on flows that coil pickoff detects detects the n of k period the corresponding moment;

Q _iI=1 ..., n; Calculate the average discharge Q of k period _k

(2) computing time occupation rate O _iI=1 ..., n; Calculate occupation rate O averaging time of k period _k

(3) storage k period average discharge, average occupancy, collection period;

Step 3: from the coil number queuing time in highway section according to estimates, its method is:

(1) reads k period coil data on flows Q from coil pickoff _kWith occupation rate data O _k

(2) calculate average vehicle of k period and sail rate λ into _k, roll rate μ away from _k

Neat Markov queuing model is estimated queuing time when (3) adopting segmentation, and the calculating queuing time is T _q(k);

Step 4: obtain average queue length from the geomagnetic type sensor of band CAN interface, its method is

(1) k period n the corresponding moment, reads in the vehicle data D that m geomagnetic sensor being with the CAN interface is captured in i sampling period from the CAN interface i sampling period ₁(i), D ₂(i) ..., D _m(i) i=1 ..., n; Regulation is numbered m near the geomagnetic sensor at crossing, is numbered 1 apart from crossing geomagnetic sensor farthest;

(2) queue length in i sampling period of calculating is from m data D _m(i) beginning is to D ₁(i) direction search searches first D _j(i)=0 data, then queue length is the length l (i) from j geomagnetic sensor to the crossing;

(3) the average queue length L of calculating k period _k

Step 5: obtain the distribution of flow in the highway section from the geomagnetic type sensor of coil pickoff and band CAN interface:

(1) in the k period, i sampling period read data on flows from coil pickoff, i=1 wherein, and 2 ..., n,

Calculate its flow average and variance,

K period flow average is Q _k,

K period flow standard difference S _Q(k),

In the k period, i sampling period read vehicle data from m geomagnetic sensor, i=1 wherein, and 2 ..., n calculates flow average and variance that each geomagnetic sensor detects;

(2) constitute the flow distribution in whole highway section by coil pickoff and m geomagnetic sensor

K period flow is at the distribution [Q in highway section _k, D ₁ ^k..., D _m ^k]

K period flow standard difference is in the distribution in highway section

Step 6 does not finish then k=k+1 if calculate, and changes step 1 over to; Otherwise change step 7 over to;

Step 7 finishes and returns.

8. method according to claim 5 is characterized in that: wherein said CAN communication controller is carried out following steps:

A, transmission flow

Step 1, described DSP of initialization and eCAN module thereof comprise:

(1) enable CAN module clock,

(2) CANTX and CANRX are set as CAN communication pin,

(3) configuration bit time configuration register CANBTC,

(4) configuration receives mask register CANGAM,

(5) configuration main control register CANMC,

(6) all positions of removing message control register MSGCTRLn;

Step 2 configuration sends mailbox, comprising:

(1) corresponding position among the clear to send request set register CANTRS;

(2) remove corresponding position among the mailbox enable register CANME, shielding mailbox;

(3) the message flag symbol register MSGID of loading mailbox;

(4) write data length is to the data length code DLC district of message control zone register MSGCTRL;

(5) corresponding position is set among the mailbox enable register CANME and enables mailbox.

Step 3 sends message, comprising:

(1) writes message to the corresponding data field that sends mailbox;

(2) the corresponding marker bit initiation message being set in sending request register CANTRS sends;

(3) etc. corresponding mailbox sends the set of response zone bit among the response register CANTA to be sent;

(4) after successfully transmission or termination send, module will send should be mutually of request set register CANTRS and reset; Step 4 sends and finishes, and returns and calls the place;

B, reception flow process

Described DSP of step 1 initialization and eCAN module thereof comprise:

(1) enable CAN module clock,

(2) CANTX and CANRX are set as CAN communication pin,

(3) configuration bit time configuration register CANBTC,

(4) configuration receives mask register CANGAM,

(5) configuration main control register CANMC;

(6) all positions of removing message control register MSGCTRLn;

Step 2 configuration receives mailbox, comprising:

(1) corresponding positions among the removing mailbox enable register CANME, the shielding mailbox;

(2) write identifier to corresponding message flag register MSGID;

(3) if the reception mask register enable bit AME of message flag register MSGID puts 1, then corresponding the reception shields and must be configured;

(4) mailbox direction register CANMD is set, corresponding mailbox configurations position is received mailbox;

(5), need be configured coverage control register CANOPC if data are protected in the mailbox;

(6) corresponding positions among the mailbox enable register CANME is set, enables mailbox;

Step 3 receives message

Inquire about the corresponding positions RMPx that the reception message of corresponding mailbox correspondence hangs up among the register CANRMP and whether put 1, accept data and finish, do not finish as yet, continue inquiry otherwise receive if then show mailbox;

Step 4 receives and finishes, and returns and calls the place.

9. method according to claim 5 is characterized in that: wherein said network communication controller is carried out following steps:

Described DSP of step 1 initialization and Ethernet controller;

Step 2 detects whether there are the data of automatic network, if having then step 3, otherwise step 6;

Step 3 judges whether it is udp user datagram protocol, otherwise step 4; If then change the UDP handling procedure over to; Change step 5 after finishing over to;

Step 4 judges whether it is tcp transmission control protocol, otherwise step 6; If then program changes the TCP handling procedure over to, change step 5 over to after finishing;

Data after step 5 will be handled are sent into described DSP and are handled, and change step 2 over to after finishing;

Whether step 6DSP has the data that need transmission, then changes step 7 over to if having, otherwise changes step 2 over to;

If step 7 has and selects udp protocol, then handle according to udp protocol, data are sent to the traffic control central computer; Change step 2 then over to, otherwise change step 8 over to;

Whether step 8 is Transmission Control Protocol, if then handle according to Transmission Control Protocol, data is sent to the traffic control central computer, changes step 2 after the transmission over to, otherwise changes step 2 over to.

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