The latest solutions for automotive measuring instruments

With the development of automobiles in the direction of comfort, safety, information and environmental protection, automobile engine development has become the mainstream of the development of the automobile industry. This article introduces the latest automotive electronics testing solutions for automotive electronic control unit (ECU) development.

CAN is an in-vehicle network that transmits information to each other through most electronic control units (ECUs) such as engines and transmissions to achieve comprehensive control of vehicles. The digital oscilloscope produced by Yokogawa Electric has a CAN analysis function, which can perform timing analysis on the CAN waveform data read into the deep memory, display the analysis results of ID, Data, and the presence or absence of ACK together with the waveform data, and can specify the ID , data specification, error specification, and frame start are used as combined trigger conditions to collect data. It can quickly retrieve partial frame data, including specified ID, Data, CRC, ACK frames and error frames, as well as Bit Stuff mixed into the frame data. Fill function) is retrieved and the waveform is displayed.

Using the above functions, you can simply observe the noise, operation, and errors at the physical level of CAN, which is helpful for the development of ECU and the analysis of program errors and failures. On the other hand, in addition to dedicated analysis functions such as CAN analysis functions, measuring instruments that support a variety of signals are also used for general automotive measurements.

The oscilloscope modularizes the input section and makes it possible to hold data on multiple channels for long periods of time. A variety of isolated input modules have more channels than a typical oscilloscope and can save collected data to a hard drive. There are also models equipped with large-screen printers for multi-channel large-screen displays.

The DL750P oscilloscope recorder produced by Yokogawa Electric is equipped with 16-channel analog input, 16-bit logic input, 1GW memory, 10.4-inch color LCD display, PC card driver, and large-capacity built-in hard drive. Module types include: three insulation modules from 100KS/S to 10MS/S, temperature module, acceleration module, strain module, and frequency module. Since it is an insulated input, you don’t have to worry about the type of signal, and can achieve long-term, high-precision, and high-interference immunity measurements. It is mainly used for the analysis of combustion pressure measured simultaneously with the rotational pulse of the engine and the evaluation of components. Because it is easy to carry, it is often used for vehicle measurement. The frequency module of DL750P predicts the deceleration curve by calculating the stop time of the pulse signal, automatically determines the stop, and accurately observes the phenomena before and after the stop. In addition, the rotation speed signal of each pulley captured by the frequency module is input into the DSP channel for calculation, and the transmission ratio can be observed in real time.

Measurement applications of power meters in automobiles

With the development of electric vehicles (EV), hybrid vehicles (HEV), and fuel cell vehicles (FCEV), power meters are used to evaluate the performance of motors, batteries, and fuel cells. The high-precision power analyzer WT3000 produced by Yokogawa Electric, recently put on the market, has a basic power accuracy of 0.06%, a measurement bandwidth from DC to 1MHz, and realizes wide-bandwidth measurement. It is a multi-functional integrated digital signal power meter. In addition, it can install up to 4 input units and is equipped with a large 8.4-inch LCD display and LED display range for greater visibility and operability.

The main measurement uses of WT3000 include: 1. High-precision power measurement of inverters in battery vehicles and hybrid vehicles; 2. Performance evaluation of high-voltage and large-capacity batteries; 3. Performance evaluation of fuel cells, etc. In order to increase the conversion power of large-scale inverters used in EVs and EHVs, it is necessary to measure the power of large currents with high accuracy. However, the current input of the power meter alone is limited, and when more inputs are made, it is necessary to combine the current sensor for measurement.

To meet this requirement, WT3000 is equipped with a current sensor that can measure with high accuracy and reduce the impact of the inverter switching pulses. Accordingly, it is possible to achieve high-precision measurement of 600A and reduce the operating hours spent on preventing pulse effects and considering wiring methods before measurement.

In addition, in order to improve the driving efficiency of the motor, the conversion method of the frequency converter is becoming increasingly complex. As a result, the frequency analysis of the converted waveform has received attention. In order to suppress the harmonic deformation of the power supply, recent power meters have a harmonic measurement mode that can analyze frequency components in addition to the normal measurement mode that performs normal power measurements. The harmonic measurement function can be used for frequency component analysis of converted waveforms. As mentioned above, the high-precision power analyzer WT3000 can measure power and analyze frequency components at the same time without switching between normal measurement mode and harmonic measurement mode. This ensures the simultaneity of the measurement values, improves the credibility of the measurement data, and makes the evaluation more effective.

Fuel Cell Testing Solutions

The core of the fuel cell test station is the process control monitoring system. Most of these systems centralize control I/O signals to a host PC, which serves as the primary user interface to the test system. Fuel cells and test systems come in a variety of types and structures, with varying channel numbers and sensor configurations. However, the signals are the same: temperature, pressure, humidity, flow and digital I/O sensed by a thermocouple or RTD.

Designing the best control I/O system requires: 1. Specialized measurement technology; 2. Various input and output structures; 3. A mechanism to prevent data loss when the network or PC fails; 4. Strong software support.

MX100 DAQMaster comes standard with an Ethernet communication interface. A single PC can achieve peer-to-peer connection with one MX100 (60ch). In addition, up to 20 MX100 (1200ch) units can be connected to one monitoring system using the same application software. If you use Visual Basic or C/C++ programming, you can implement more channel systems. In a fuel cell system, if the control I/O is improved and optimized, it will make a big difference. Most data acquisition systems provide a modular structure. Different sensors require different modules. All channels of the MX100 can provide universal input. This means each channel can be individually assigned voltage, thermocouple, RTD and DI input types. In addition, each MX100 can manage three different hardware scan groups simultaneously. This provides great flexibility in mixing systems with fast I/O signals (pressure, humidity, and flow) and slower I/O signals (ambient temperature, DC voltage, etc.).