Introduction of automotive electronic test system solution

As the car electronic system increase, it is the challenge for the test engineer in China on car system highly mechanical and electrical integration testing. As for car issues involved in the process of research and development, let's introduce satisfy engines, yokogawa motor drive, vibration, environmental impact, fuel battery efficiency and CAN bus testing complete solution.

One, foreword

With the development of automobile industry and electronic industry, more and more electronic technology has been applied in modern cars. Car will be from a mere mechanical products to develop in the direction of advanced electromechanical integration products. Because the real-time information of driving system and multimedia equipment popularization in the car, the car more personalized, versatility, safety and comfort. Wireless and mobile computer technology rapid development, even driving alone in a strange land, also won't feel lonely or lost. Car in people's life is not just walking tools, and gradually become a way of enjoying life. Research in the field of automotive electronics become the most active part of the automobile research and development achievements in this aspect, will achieve more in the market returns.? Automobile research and development, the author of this paper involved in the process of the engine, drive, vibration analysis, environmental impact, the fuel cell efficiency analysis, CAN bus, etc., introduce yokogawa electric motor to provide all kinds of test solutions (figure 1).?

Second, the electric car fuel cell test?

For engineers engaged in automotive research and development, in testing the following aspects are the important factors influencing the test efficiency and results:

(a) all kinds of high frequency and low frequency, high power and low power of electromagnetic radiation interference?

(2) the common-mode electricity 圧, vibration, changeful environment?

(3) the reliability of the data collection and analysis?

(4) when the road test instrument of power and energy consumption?

(5) movement and field use?

Through test engineers communicate with auto production research and development enterprise, yokogawa motor continuously improve its product and make it more adapt to the needs of the development of automotive research. For example, in order to meet the needs of the electric car fuel cell research, yokogawa motor on the basis of DARWIN series developed? DAQMaster MX100 series.?

Because each battery only 0.8 1.5 VDC output, in order to output enough electricity. Fuel battery generally consists of about one hundred monolithic battery, automotive applications, in particular, the battery pack will be composed of six hundred monolithic battery. Battery voltage monitoring (?CVM) system by testing each single battery voltage of battery pack structure can detect the battery has a problem; The analysis or the loading long battery performance at runtime.

Detect the battery voltage is used when the differential input. Although single battery voltage is not high, but produces differential input terminals of the test instrument to carry several hundred volts. This voltage is called the common-mode voltage. Most of the data acquisition instrument (?DAQ) without insulation, the input voltage limits are generally 5 v or 10 volts. In addition, the insulation instruments often susceptible to the influence of the ground loop. In order to overcome the fuel cell CVM system high common-mode voltage, high voltage insulation. Although you can use the external signal converter or cache, in order to reduce the volume and low cost between guarantee signal resolution and accuracy at the same time, now many built-in cache of DAQ system.?

DAQMaster can provide the highest level of the channel over the ground, between modules and isolation between the channels. In addition, its modular structure and standard software makes MX100 is easy to implement monitoring of battery voltage up to 1200 channels.?

And to achieve high voltage insulation and multi-channel DAQ system design is A problem, because most of the data acquisition instrument module USES A single A - D converters with front-end multiplication or scanning. High common-mode voltage signal after insulation transformer and A - D converters before insulation and discretization must through the relay.?

MX100 use yokogawa patent technology of high pressure in scanner solid-state semiconductor? Relay to achieve the multi-channel switch input signal, the relay by high pressure (1500 VDC), low? Leakage current (3 na)?MOSFET (metal oxide semiconductor field effect transistor) and the output voltage of photoelectric coupler, 10 with a 1 second cycle channel high speed scan, non-contact, long life, no noise, etc.?

In addition,?MX100 inside the insulation of the transformer and integral type A - D converters is yokogawa patent technology. Other DAQ system using electromagnetic relay to provide insulation, can produce switch time, stability of the switch, and daily maintenance. Finally, MX100?DAQMaster?Provide high performance insulation and 4 channels at the same time sampling, because each channel 4 channel module of hardware adopts independent hardware.?

To represent the waveform, correctly? Sampling rate is very important, high speed acquisition can get correct data. Therefore MX?

100 the minimum 10 ms measurement cycle, and a system can be used mixed 3?Kind of measuring cycle, measurement cycle can be set for each module separately. The maximum capacity of 2 g MX100 support? Bytes of CF card and start the data backup when communication failures. When communications back to normal, to begin automatically transmit data to the PC.MX100 for fuel cell test of high-speed multi-channel/high pressure/multicycle characteristics, help engineers improve the testing efficiency and accuracy.?

Three, CAN bus is analyzed

Widely used in the car the car bus technology. All sorts of complicated electronic equipment for car interior car bus, controller, measuring instruments, etc. Provides a unified data exchange channels. By the electronic control unit (on car?ECU) control more and more the number of components, such as electronic fuel injection equipment, idle speed control (ISC), anti-lock braking device (?ABS), airbag device, electric Windows and doors equipment, active suspension, etc. With the widely application of the integrated circuit and single-chip microcomputer in the car, the car more and more the number of ECU.

So, a new concept - the car controller, the concept of local area network CAN also arises at the historic moment. CAN by Germany BOSCH company was the first to solve the problem in the modern car data exchange between control and test instrument and the development of a data communication protocol, in accordance with the relevant ISO standard, the CAN bus topology is, so also known as the CAN bus.?

With the wide use of CAN bus in the car on the research, development, production and maintenance of each link of bus signal testing and analysis is becoming more and more important, especially in the observation and analysis of noise signal? Due to cable wiring length, terminal impedance, position of reflection noise or by connecting plural contact overload LEVEL changes caused by the abnormal phenomenon, CAN use DL7400 series CAN trigger signal, CAN bus CAN capture the signal and display the waveform. According to the CAN protocol analysis and waveform signal in the form of a list shows together. Trigger condition CAN be set into the CAN data frames (ID? The Data,? RTR? Fields of the bits, etc.) or more fields. Trigger can be activated when error frame. CAN be captured on the timeline of CAN bus waveform data analysis, each frame ID and data displayed in hexadecimal or binary symbols.?

Four, ABS work when the battery voltage fluctuation?

ABS control device by comparing from attached to each wheel speed sensor signal monitoring whether the wheel is locked. When the ABS control device to detect after a wheel is locked, it will send a signal to ABS actuator to open the valve. ABS actuator including spiral pipe valve, pump, motor, brake fluid tank. Open the valve can be instantly reduce disc hydraulic, braking, can restore the wheel speed.

Then quickly improve disc hydraulic again, by ABS actuator increases braking force. In other words, can increase or decrease in disc brake hydraulic pressure to prevent being locked. Increase the disc hydraulic press is the pumping liquid into the cylinder, can make the pump motor work quickly. This quick motor will affect the control of the spiral pipe valve PWM current signal. Does this affect the battery cannot be obtained general ABS operation voltage fluctuation. Therefore, it is necessary to observe the battery voltage fluctuation.

Using DL750? Max. 1 gw long memory can capture high-speed sampling from start to finish all the process of braking action. It also can capture the whole process, using the zoom function test one of the irregular parts in detail. This function can automatically set the waveform parameter automatic test area, including the magnified area. The zoom function can not only accurate testing in a cycle of irregular parts also can automatically test the waveform parameters of amplification area?.?

Five, the power steering control ECU (contain? Converter)/motor development

Power steering (EPS) applied in the small car has been one of the more popular, but in large cars need high torque applications need to use 3 phase motor. Unlike conventional DC machine, three phase ac motor need power meter testing power and efficiency. In addition, the ECU by CAN bus communication,? They must test CAN bus signal.

DL7400 CAN be specific for CAN bus ID/Data trigger, synchronous observation with other signals. General oscilloscope DL1640 / DL1740, can test the ECU of the CPU signals, using 100 MHZ differential probe and 150 a current probe can also test the motor of the surge current, etc.DL750 up to 16 ch insulation input, is suitable for the inverter input and output voltage/current and the ECU control signal for a long time observation.

WT1600 large car EPS can measure the one end of the drive system with 3 phase inverter DC, 2 times the three phase current/voltage/power, inverter efficiency. Power can be accumulated for the operation mode of a specific test. Using WE7000 time module/CAN/isolation of A/D module/temperature module CAN realize multi-channel comprehensive test. Steering Angle current/voltage/temperature/consumption at the same time, through long time test. The data on the use the CAN module CAN be a CAN bus at the same time into a physical quantity to realize test at the same time.

Six, di diesel engine injection experiment?

Di diesel engine can reduce fuel costs and purifying exhaust emission. The following is the key to its development - high pressure injection and electronic control performance evaluation method is put forward the solution:

(a) Mechanical parts design value evaluation (injection time and injection pressure)?

The test object is the nozzle spray out the fuel injection pressure, engine speed change and nozzle solenoid valve switching time. Engine development requires a dynamic test (gradually increase engine speed check whether comply with the design requirements) and static test (in fixed condition check whether stable running speed).?(2) with the ECU control signal synchronous test?

With the ECU control signal synchronous test, test the ECU timing and actual injection timing.

Seven, the article summary

Due to the vehicle and parts company all over the world have extensive cooperation, yokogawa motor in this area have a lot of test cases. Yokogawa electric hopes for contributions to the development of automotive electronics.

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