What is the role of car OBD

The full name of OBD is on-borad diagnostics, which is commonly called the on-board diagnostic system in the industry. It was originally designed as a professional instrument for 4S shops to detect engine failures and exhaust emissions. With the development of science and technology, it has been popularized by ordinary car owners. Just plug the wireless adapter into the OBD interface, you can automatically read the data, connect to the mobile phone via Bluetooth, and open the mobile APP to view the data. In addition to fuel consumption display, there are real-time driving data display, trip cost analysis, engine fault detection and maintenance reminders.
On-board OBD can also display real-time driving information. Just start the engine and the adapter will automatically connect with the mobile phone. You can see real-time data such as fuel consumption, engine speed, water temperature, and vehicle speed through the mobile APP, which are all digital real-time displays, which is very convenient to read. In addition, there is a voice broadcast function, so that the owner can grasp the driving conditions of the vehicle at all times.
In addition to the above functions, the on-board OBD also has an intelligent positioner that can record the vehicle’s driving trajectory. At the same time, a new sensing function can monitor the vehicle’s dynamics during the driving process, such as when the fuel consumption is the lowest or highest and when the brakes are sharp Etc. will be recorded and summarized. In addition, there is the fuel consumption cost that everyone is most concerned about. The mobile APP will automatically calculate the trip cost based on the pre-entered oil price and the average fuel consumption per trip.
At the same time, the on-board OBD can not only detect automatically, but also directly show what faults occur in the engine. In this way, the owner can call the technical maintenance master in a timely manner according to the prompt fault, whether the vehicle can still run normally or how to deal with it.
On-board OBD can also monitor the vehicle remotely with the help of cloud technology based on demand, with anti-theft positioning, remote detection of engines, electronic dogs, and violation inquiry, etc., with more comprehensive functions.
The realization of these functions needs to collect relevant data through the OBD interface. This is mainly through the CAN bus to implement data interaction. Of course, some models do not use the CAN bus, but the principle is the same.
数据 What data is collected by the OBD interface
1. CAN bus data
CAN bus data is the data needed for each control module to interact. For example, the accelerator pedal position signal is transmitted to the engine through the sensor, and this signal is also the most basic input signal for the automatic transmission. Therefore, the engine control module will send this signal to the CAN bus all the time, and the transmission control module reads it in real time. Take this signal.
Because the bus data is used for interaction, the data flow has always been on the bus, so it is only necessary to collect these data to read. The principle is relatively simple, and a lot of information can be found by searching, which is not expanded here.
The data on the CAN bus has been relatively rich: vehicle speed, various temperatures, wheel speeds, engine torque, throttle, brake pedal, gear lever position, air conditioner and other various equipment are working, fault information … a lot. The characteristics of these signals are generally: the data required by different control modules.
2. Controller internal data
Simply simple, CAN bus provides you with a channel for data circulation. Through this channel, the acquisition device sends instructions to the relevant controller, and the controller returns relevant data. In this way, various variables in the controller software operation can be collected, so almost all data can be collected. Because more instructions are sent, it consumes more resources. The richness of this data is far greater than the former. But only the developer may know how to configure to collect this data.
The fact that no data can be recorded does not mean that all data can be recorded. Especially for controller data, there are too many to read. Even if you buy the most expensive device, you can only record a small part because of the limited bandwidth. The collection of data inside the controller is also related to the capabilities of the controller itself. The controller of the production vehicle is relatively weak, and less data can be collected at the same time. Vehicles used for development use more powerful controllers.
In general, there are two main types of data that can be obtained from the OBD interface. One is specified in the OBD standard, and the other is manufacturer-specific data. Generally, the manufacturer-specific data must be obtained from the manufacturer’s agreement or mid etc. to get.

Post time: Nov-29-2019