Application of Digital CAN Bus Instrument on Road Roller

I. Overview

Since 2001, Europe and the United States have successively implemented the second-stage emission regulations for off-highway vehicles. To meet this emission regulation, more than 10 liters of engines must use electronic control and air-to-air cooling technology to meet the requirements. Since 2005, Europe and the United States will implement the third-stage emission regulations for off-highway vehicles. All engines can only meet the requirements by electronic control and air-to-air cooling technology.

The electronic control technology in the engine refers to the unified intelligent management of the engine speed control function, fuel system, data acquisition, fault diagnosis, etc. by using an electronic control unit (ECU). Among them, the data transmission uses the controller LAN and the internationally recognized standard protocol J1939 to build the network. How to fully utilize the electronic control technology of the engine. The first point is to use the CAN bus technology to detect and control the electronically controlled engine from time to time.

In 2005, our company's road roller began to be equipped with an electronically controlled engine. The first roller XD121 was equipped with a QSB 3.9 Cummins engine. This year, digital bus meters began to be applied for the first time and showed a strong advantage.

Second, MURPHY instrument introduction

PowerView is a powerful digital bus display instrument produced by MURPHY Corporation of the United States. It displays the engine's many different parameters and service codes for the equipment operator. In other words, PowerView is like a window to observe the operation of an electronically controlled engine.

★PowerView appearance

★PowerView interface

After the power is turned on, if the engine has a pre-start procedure, PowerView will display “WAITTOSTART”. The operator can start the engine when the screen no longer displays this information. Once the engine is started, the engine parameters will be displayed on the screen. As shown in Figure 3. Depending on the parameter settings, there can be single page display and page display. A single page can only display one engine parameter that is prefabricated, but you can use the arrow keys to display other parameters. The sub-pages can simultaneously display the pre-made four engine parameters.

On the engine parameter page, press the “Menu” button to enter the main menu. As shown in Figure 4, seven options are displayed on the screen. Scroll through the “arrow keys” and press the “right button” to scroll continuously. The remaining options are displayed.

Third, the application on the road roller

The digital CAN bus meter has been initially applied in our company's road roller. It is mainly used in the full hydraulic vibratory roller. The products that have been applied include XS191D, XS122D, YZC12G, XD121, etc. After the CAN bus meter is configured on these products, It shows a lot of advantages. First, it can save some engine display instruments such as oil pressure gauge, water temperature meter, tachometer, hour meter, etc. It can save some indicators such as fault diagnosis, oil pressure alarm, water temperature alarm, etc. The layout is very simple, clear and beautiful. Figure 4 shows the XS191D dashboard layout. Second, it can display some important parameters that have not been seen before, such as fuel combustion efficiency, fuel consumption, engine load and historical faults. It can have a deeper understanding of the engine and play an important role in engine maintenance. Third, the working principle is simple and the wiring is convenient. As shown in Figure 5.

★ The XS191D instrument panel eliminates the tachometer, oil pressure gauge, water temperature gauge and various alarm lights. The XS191D instrument panel is very simple and beautiful.

★Working principle When the MurphV bus instrument is applied on the roller, the wiring is very simple. Firstly, a 12VDC or 24VDC power supply is connected, and then connected to the engine controller through the CAN line, so that data transmission can be performed. In addition, PowerView can also be equipped with 1.16 pointer meters, which directly reflect the data that important drivers often look at. Pay attention to the following points when connecting the line:

1. A 120 ohm resistor should be connected between CAN high and CAN low near the PowerView terminal.

2. The cable used should meet the control requirements of SAE J1939.

3. RS485 shielded wires should be used when connecting PVA meters.

4. If the backlight regulator is not used, the backlight should be grounded and not connected.

Fourth, the conclusion

The digital CAN bus meter has achieved good results after being applied on the road roller. It has made our company's road roller one step ahead in the application of advanced technology and improved the technical level of the whole machine.