Foreword
Electronic science and technology develop rapidly, electronic product emerge in an endless stream, as main the intersection of power and source battery, its power supply capacity and safe reliability are paid close attention to day by day. Research and develop and produce the indispensable links of stage as the battery, the traditional characteristic observes and controls high artificial dependency, measure the inefficiency, the network, intelligence and automation also can’t meet the realistic demand.
What this text put forward has already realized and the applied solution can be multi-channel move ahead simultaneously to real-time monitor the test state of the battery in the whole journey, finish the monitoring disposition of PC end before testing first, return to the online connected state of the electrical relay in real time through RS485 interface and CAN bus, and then control the opening with the corresponding electrical relay of test item type according to the demand. After monitoring beginning, on battery voltage, electric current and PC that the temperature transmits the control room when information is real, can reflect that tests the variation tendency of quantity through the flexible online editor’s data curve, can also be looked over the situation of the key point by the historical data recorded at the same time.
Requirement analysis of the system function
According to the current demand, the overall function in need of realizing of the system is as follows,
(1) Acquisition of signal and integrity test of the control circuitry: The test item of the battery charges, nominal and shorts out, surveys shorting out, overfall and discharges, discharges and discharges and protects etc. by force, before testing, can feedback electrical relay signal and measuring instrument current value reflecting actual hardware connection and corresponding to the integrity of the controlling circuit with the test item to P through RS485 and CAN C controls on interfaces.
(2) It is tested that the security is convenient with automizing: Controlling interfaces should have emergency stop buttons, through controlling the scram electrical relay can cut off the test line effectively while meeting accident, keep and test the state for the recovery testing after the removal of faults at present at the same time. Dispose the limit of battery voltage, electric current and temperature before testing, control testing time at the same time, stop testing while meeting the burst situation or reaching and preserving the goal automatically.
(3) Test data recording and deal with: Confirmed that samples the time interval, the real-time display in the form of curve of data by the demand, coordinate time and very automatic dynamic alignment of the data quantum observe the trend need in order to meet. Data store, choose efficient the intersection of binary file and form in real time, historical data derive return, have all right one way or the other to select: Excel form and curve form. The intersection of curve and very flexible editor, translate, part enlarge narrow and multiterm curve form apparent and how apparently, etc. Cursor can the intersection of tracing and curve move and combine the dynamic display number value in addition.
Systematic hardware design
,Known by the requirement analysis of the system function, this battery of safety monitoring systems can be divided into three parts, including data acquisition floor, the transport layer of the data and data treated layer on subscriber station PC. Users start the test item preserved by control relay circuit of the one-chip computer, the real-time display battery data of the measuring instrument, and is gathered by the one-chip computer through RS485 interface, then gather the one-chip computer and draw the valid battery real time data of integration on PC via CAN total line transmission. The battery monitors the real-time curve of software and reveals and stores the battery data received, and compare synthetically with relevant historical data up to standard,etc., analyze the reliable safety of the battery. Depend on the interlaminar communication protocol, one layer of modular designs of the monitoring system of the battery has improved maintainability and expansibility of the system.
A battery of safe projects of Fig. test the systematic overall design block diagram
Originally design choosing XC2267M one-chip computer of C166SV2 framework of strengthening of possession that Germany Infineon Technologies Company introduces, integrated voltage regulator and many kinds of Shakers, have ultralow and power consumptive awaiting the opportune moment and mode of operation. The measuring instrument chooses one gram of intellectual digital display meters of intelligent instrument Co., Ltd. of Hajto, there are RS485 serial communication interfaces, upper and lower limit alarm relays are exported (250V/3A) ,The frequency reachable 10Hz of quantity, the available quantum measures the dynamic auto-switch of the number value at the same time.
An electrical relay circuit control
Requirement analysis of can follow the system functioning, knowing to require the intersection of battery and the intersection of monitoring circuit and the intersection of integrity and the intersection of check sum and end of test or the intersection of accident and effective key-out in time take place, test, to the intersection of one-chip computer and the intersection of electrical relay and control panel.
Fig. 2 is that the chip of the electrical relay control the circuit diagram, reflect actual hardware connection and correspond to the intersection of controlling circuit and 4# of electrical relay signal passing ST and the intersection of 5# and ST of integrity reach by total line transmission via mouth and CAN, IO of one-chip computer, with test item Control it on interfaces. Control PC end, turn into the one-chip computer and outputs the level level of the pin through the intersection of CAN and control command that bus line send out, open and shut through pin 4# Load and control relay, Load of 5#, via electrical relay chip pin 4# Rly and 5# Rly and then.
Fig. 2 electrical relay chip controls the circuit diagram
2 data acquisition and transmitting
Measuring instrument and battery data acquisition one-chip computer carry on communication through MODBUS/RS485 serial port, the operating mode of the network is set up as half duplexly, through controlling the one-chip computer to output the level level of the pin to touch off and realize, the interface adopts and shields the line transmission of the twisted-pairs. RS485 interface adopts the association which equilibrates driver and differentiating receiver, antijamming capability is strong, can realize that stand more and unite the speed communication of the net height, and the interface signal level is low, chip of the indefectible interface circuit.
CAN(Controller Area Network) It is a kind of field bus with cost performance and great at the same time of the international standard, interfere with environment lay whom reliable operation developed by Company, Bosch of Germany, for distributed system in strong battery, this serial data communication network can support distributed control and real time control effectively, the wrong verification characteristic of the hardware has strengthened its error correction and antijamming capability, Gao Da 1Mb/s’ message transmission rate makes real time control realize easily. CAN bus line adopts the main competition type bus structure more, has the characteristics that the multistation runs and disperses arbitral I2C and broadcast communication, can realize the communication of freedom among node.
A typical CAN node is formed by MCU and CAN transceiver with CAN control device. CAN transceiver sets up the connection between CAN control device and physical bus line, the transmission between CAN control device and total collinear physical layer of physics of level signal of control logic. CAN control device carries out CAN agreement, is used in information to buffer and filter.