Application of wireless remote control technology in LHD



1.Working condition of remote control LHD

In the process of tunnel production, due to the particularity of long-term excavating and mining technology, the mining conditions become more and more complex. In the process of shoveling and discharging, the ore from each access continuously collapses into the mining area. Therefore, a lot of extracted ore drift form large blocks and hanging arches, which makes the driver have potential safety hazards in the process of shoveling and discharging. In addition, due to the safety problem, the conventional practice of the ore in the mined out area is to give up the stope, resulting in the waste of resources. Through various demonstrations, with the help of the national and company's intelligent and green mine development plan, driving the transformation and upgrading of traditional mining industry with informatization, automation and intelligence, and build a "safe, green, intelligent and efficient" mine development goal. The remote control LHD is the first step of the development of mine mechanization to automation and intelligence.

2. Development trend of LHD remote control technology

The development of LHD remote control technology is mainly divided into three stages:

The first stage: Line-of-sight remote control. Generally, the operating distance is 50m ~ 100m, no network is needed, so the one-time investment cost is low. Advantages: safe to use, easy to operate and maintain, can reduce labor intensity. Disadvantages: it largely depends on the judgment, operation technology and experience of the operator. It can't judge the loading condition of the LHD very well, the production efficiency is low, and the running state of the equipment can't be fed back in real time.

The second stage: Line-of-sight video remote control. In the range of 50m ~ 100m, the video transmission mode is used to operate the equipment, which does not need to set up a network and has high cost performance. Advantages: remote control is realized through camera and monitor images, which is easy to carry, safe and guaranteed for people to stay away from dangerous areas, and the display screen can feed back the operation status of the equipment in real time. Disadvantages: the requirements for underground environment are relatively high, and the operators are still operating equipment around the stope, which is dusty and has poor vision.

The third stage: Tele remote control. Based on the combination of autonomous driving technology and remote control technology, the underground environment and equipment status are transmitted to the surface central control room, and the operators conduct real-time remote operation according to the monitoring screen to completely change the operating environment and operation mode.

3.Principle and Implementation

Wireless remote control technology is the technology of remote control for the controlled object. The principle is that the transmitter first encodes the controlled electrical signal, and then converts it into a radio wave to send it out. The receiver receives the radio wave containing information and gets the original control electric signal through receiving, amplifying and decoding, this electrical signal is used for power amplification to drive related electrical components and realize wireless remote control.

WiFi is a kind of technology that can connect terminals such as personal computers, handheld devices (such as pad, mobile phones) with each other in a wireless way. It is the most widely used wireless network transmission technology today. In fact, it is to convert wired network signal into wireless signal, and use wireless router to receive relevant computers, mobile phones, tablets, etc. supporting its technology. WiFi signal transmission speed is very fast, does not need wiring, in line with the needs of personal and social information.

Alpha's remote control LHD construction process is as follows:

  • The first phase and the second phase have the same basic principles, but the difference is that the first phase uses the data transmission mode, and the second phase uses the data transmission and the figure transmission synchronous transmission, the principles are as follows:

No alt text provided for this image

The LHD wireless remote control system is divided into two parts: wireless transceiver and remote control. Through the 2.4G point-to-point wireless transmission module with power amplifier, it can realize the remote communication of the LHD field data collection and operation control, remote real-time monitoring, status display, parameter setting, record saving and deep-seated back-end data processing; The wireless transceiver reads the scraper data through CAN communication, including: monitoring parameter sensor (2), vehicle TCU (3), power output (4), point-to-point outgoing module (5) with 2.4G power amplifier and engine ECU (1); the remote control part includes 2.4G wireless access module (6), remote control processor (7); The parameter detection sensor (2) installed on the LHD measures the operation status data of the LHD, which is sent to the on-board TCU (3) after signal conditioning. The on-board TCU (3) calls the corresponding automatic shift strategy according to the relevant data transmitted by the speed sensor, pressure sensor, gear selector, accelerator pedal sensor and engine control unit, and drives the relevant shift solenoid valve and 2.4G belt Point to point outgoing module of power amplifier (5); At the same time, the wireless communication between the vehicle terminal and the remote controller is realized through the 2.4G point-to-point transmission module (5) of the wireless transceiver with power amplifier and the 2.4G transmission module (6) of the remote controller.

  • In the third stage, WiFi wireless network and radio remote control technology are applied to the LHD to realize long-distance wireless operation. In the remote control mode, the driver can control various actions of the LHD through the wireless remote control handle unit in a safe area far away from the LHD. In the production efficiency has been greatly improved, and also to a large extent to protect the health of drivers and life safety. The specific principle is as follows:

No alt text provided for this image

No alt text provided for this image

No alt text provided for this image

Display system frame diagram

The whole display system design follows the principle of ergonomics and adopts the modular design method. The whole system can be divided into operation data display module, status data display module and video data display module. The data of the operation display module comes from the controller. After the controller collects the action of the operation mechanism, it sends it to the LCD through the CAN bus after processing, so as to display the command signal for the operator; The video display module includes the front and rear LHD video display. The scene around the LHD is photographed by the camera with WiFi, and the scene is returned to the upper computer through wireless LAN. The video is decoded and displayed on the upper computer to provide the operator with a real sense of driving operation; In the status display module, the vehicle terminal receives the status parameters of the LHD collected by each sensor, and then sends the data to the upper computer through its own WiFi to update the parameters of the upper computer interface, so that the operator can understand the operation status of the LHD.

Set up control system and monitoring system on the console. Through the handle and other operating mechanisms on the operation platform, the driving and action of the LHD can be controlled remotely. The operator carries out necessary operations on the knobs, buttons and handles on the operation platform, this operation action is compiled by the controller and sent to the upper computer, and then remote control the start, speed change, steering, throttle and brake of the LHD through the wireless network, so that it can drive according to the required speed and route, so as to realize remote control and monitoring of the LHD. 

At the same time, the real-time images and operation parameters video signals of the front and rear road conditions of the LHD are transmitted to the upper computer display screen installed on the operation console in real time through the wireless network, so that the driver can master the real driving environment of the LHD in real time and remotely, so as to monitor the operation of the LHD. In this way, the LHD, the remote driver and the remote control console (remote control platform, none The circuit consists of, camera, control system, etc.) to form a closed-loop control system.

The features of remote control system are as follows:

1) Keep all functions of previous manual driving, without changing the operation habits and functions of the original vehicle;

2) At the same time, it has the function of remote control, which can be used for remote control. The specific basic functions are as follows:

a. The remote control range of the remote control system is not limited by the distance;

b. Control the boom up and down, and the speed of action is controllable;

c. Control the loading and unloading of the bucket, and control the speed of the action at the same time;

d. Control the stick oil cylinder to extend and retract, and the speed of action can be controlled at the same time;

e. Control forward, backward, left and right turning, and control the speed of the action;

f. Control rotation and control the speed of simultaneous action;

g. Control the start and stop of the engine;

h. Switch for controlling front and rear lights;

i. Switch for controlling horn;

j. There are 4 video surveillance images, respectively monitoring the front, rear, left and right four directions of the scraper.

4. Epilogue

Through the comprehensive application of computer technology, wireless network and wireless remote control technology, mine safety of underground personnel is improved, labor intensity is reduced, production pressure is greatly relieved, and the effect is remarkable. At the same time, Alpha is promoting the construction of intelligent mines, and remote-control shoveling technology is the general trend. Now, the remote-control LHD manufactured by Alpha will summarize experience for it to implement remote-control LHD, and take an important step towards the transition from mechanization to automation and then to intelligent development.

Contact us: