CN103217978A - Control method for implementing coordinated operation of multiple vehicle groups of hydraulic heavy duty truck - Google Patents

Abstract

The invention relates to a control method for realizing coordinated operation of multiple groups of hydraulic trucks, which can realize unmanned automatic driving of roadway trackless wheeled hydraulic trucks. The principle of ultrasonic distance measurement is applied to determine the position between the vehicle body and the roadway. The various information measured by the vehicle through the ultrasonic distance measurement sensor is transmitted to the central processor through the various information measured by the ultrasonic distance measurement sensor. The set program calculates the car body speed, steering angle, walking trajectory, path and other information relative to the roadway, and uploads the position information to the CAN bus system for calling by the next car. Download the attitude information of the vehicle in front, and according to the attitude information of the vehicle in front, the processor calculates the geometric parameters required to track the trajectory of the vehicle in front according to the control program, and then determines the trajectory of the vehicle, so that the vehicle behind can automatically track the vehicle in front. Thereby, the steering control of the split load transport vehicle is realized.

Description

A Control Method for Realizing the Coordinated Operation of Multiple Vehicle Groups of Hydraulic Trucks

technical field

The invention belongs to the technical field of measurement and control, and relates to a control method for realizing the coordinated operation of multiple groups of hydraulic trucks, which can realize unmanned automatic driving of roadway trackless wheeled hydraulic trucks.

Background technique

In mining, heavy mining and supporting equipment under the mine often need to be transported and transferred to the working face by hydraulic trucks. Due to the complex terrain of the roadway and the narrow space, it is difficult to control the hydraulic truck during the transportation of equipment. The existing underground roadway hydraulic trucks are driven manually. During the actual operation, the special environment of the underground roadway can easily affect the driver. Due to the narrow space of the underground roadway, the driver must maintain a high degree of concentration for a long time. If the control is improper, the truck may scratch and collide with the roadway wall or hydraulic support equipment, and even cause major safety accidents such as roadway collapse. Therefore, the driving of the existing underground roadway hydraulic truck has high requirements on personnel and high risks, and it is difficult to ensure safe production under special conditions in the underground.

Contents of the invention

The purpose of the present invention is to solve the above problems and provide a control method for realizing the coordinated operation of multiple groups of hydraulic trucks. Based on the control method, unmanned automatic driving of multiple groups of hydraulic trucks with trackless wheels in roadways can be realized.

The present invention sets out from solving practical problems, has adopted following technical scheme:

(1) The hardware system includes ultrasonic ranging system, CAN field bus system, central processing unit, human-computer interaction system and execution system;

(2) Applying the principle of ultrasonic ranging, using ultrasonic ranging sensors to collect the distance information between the car body and the roadway wall in real time, so as to determine the relative positional relationship between the car body and the roadway wall. At the same time, the ultrasonic ranging sensor adopts explosion-proof Processing, adapted to the special environment of the underground;

(3) The information measured by the vehicle in front through the ultrasonic ranging sensor is sent to the central processing unit, and the central processing unit calculates the vehicle body speed, steering angle, walking track and path relative to the roadway according to the set program. information, and upload the location information to the CAN bus system for the subsequent vehicles to call;

(4) Each car in the EMU has an independent processor. The rear car processor downloads the attitude information of the front car from the CAN bus. According to the attitude information of the front car, the processor calculates and tracks the movement trajectory of the front car according to the control program. The required geometric parameters, and then determine the trajectory of the vehicle, to achieve the purpose of the rear vehicle automatically tracking the front vehicle, and the distance between the two vehicles remains constant during the tracking movement process;

(5) Each car in the EMU is connected end to end to form a series system. The movement of the front car can be recognized by the rear car in real time. The rear car controls the movement of the car according to the attitude information of the front car, and the attitude information of the rear car is uploaded to the bus. system, so that the next car has motion reference information and realizes the coordination of multi-vehicle groups;

(6) The processor of each car in the EMU, on the basis of tracking the movement trajectory of the preceding car, summarizes the distance information between the car body and the roadway wall measured by the ultrasonic ranging sensor of the car in real time, and each car in the EMU The hydraulic system of each vehicle includes a PLC control system. The PLC controller of each vehicle independently controls the hydraulic components such as valves, pumps, and motors, and adjusts the posture of the vehicle to ensure that the rear vehicle does not scratch or collide with the roadway wall, and realizes Automatic correction of the car;

(7) In order to realize the coordinated operation between the straight running and turning of each car of the EMU, the software system adopts a modular design, that is, the main program can be divided into several blocks, each block has different functions, and there are more in the program library. The extended program blocks of the EMU can be used to complete different actions through the combination of different program blocks, thereby expanding the working range of the EMU;

(8) The present invention can adopt a single-person driving or manual remote control power source vehicle, and the follow-up hydraulic vehicle automatically tracks the track of the preceding vehicle. security risks.

The central processing unit is an ordinary electronic computer or an industrial computer.

The execution system is composed of hydraulic components of the hydraulic truck, and the PLC controller of each vehicle can control the hydraulic components to perform corresponding actions.

The ultrasonic ranging system is composed of an ultrasonic sensor, a temperature compensator, and an A/D converter, which can measure the distance between the car body and the roadway wall, and convert the information into an electrical signal; the ultrasonic sensor is composed of a transmitter and a receiver. The ultrasonic sensor emits ultrasonic waves, which are received by the receiver after bouncing off the roadway wall, and the distance between the car and the wall is calculated according to the time difference between transmission and reception. The propagation speed of ultrasonic waves in the air is known as u, and the time difference t in the process of ultrasonic waves from being emitted to being reflected back by obstacles is measured. The measured time difference is multiplied by the speed of sound to obtain the distance traveled by the ultrasonic wave during the round trip, and the measured distance S is half of the sound wave transmission distance:

$\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; ut</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}$

The receiver converts the ultrasonic signal into an electrical signal, and the A/D converter converts the electrical signal into a digital signal. The signal output by the ultrasonic sensor is transmitted to the central processing unit through the CAN field bus. The central processing unit judges the position and posture of the vehicle according to the data collected by each sensor, and sends a control signal according to the judgment. The control signal is transmitted to each PLC control by the CAN field bus. The PLC gets the control signal, outputs the response signal, and finally transmits it to the electrical control device of the valves, pumps, motors and other hydraulic components of the hydraulic truck, so as to control the hydraulic components to perform corresponding actions, and then control the movement of the car, and finally realize the EMU The purpose of coordinating steering and going straight in each workshop.

According to Article 3.1.2 of GB50419-2007 "Code for Design of Roadway Sections and Intersections in Coal Mine", the shape of the roadway section can be divided into rectangle, trapezoid, arch, horseshoe and circle; according to Article 4.1.3 of the design code It is stipulated that the net section of the transport roadway should be designed according to the size of the transport equipment operating in the roadway and the largest piece that needs to be transported, and should be checked according to the size of the largest piece that is occasionally transported and the ventilation capacity. Since the width of the hydraulic truck is equivalent to the width of the large equipment in the mine, the hydraulic truck can work in the mine roadway that meets the national standard. According to Article 4.3.2 of the design specification, the minimum safety clearance between trackless transport equipment and roadway side supports, pipelines, and facilities is 600mm, and the detection range of the ultrasonic ranging system includes 600mm. At the same time, Article 4.1.1 of the design code stipulates that the main transport lanes and main wind lanes, and trackless lanes shall not be less than 2m, and the preparation roadways in the mining area and the transportation lanes and return air lanes of the coal mining face of large and medium-sized mines, and medium-thick coal seam , The thick coal seam shall not be lower than 2m, and the thin coal seam shall not be lower than 1.8m. Since the hardware composition of the control system is relatively small, it has no influence on the height of the hydraulic truck. To sum up, the trackless wheeled hydraulic load-carrying EMU applied the EMU coordinated operation control system can well implement the steering and straight-going coordinated operation of each workshop in the underground roadway, and can realize remote control or unmanned driving. Autopilot.

Since ultrasonic ranging is a non-contact distance measurement technology, it has good operability in underground roadways, and temperature compensation and other technologies can be used to process ultrasonic ranging signals to ensure its stability and accuracy; CAN field bus technology is adopted, and the posture information of each car can be transmitted smoothly and in real time through the bus system; for the form of coordinated operation of the EMU, a serial and independent control mode for each workshop of the EMU is designed, so that the EMU can be formed. At the same time, each car has a certain degree of autonomy, which is convenient for the coordinated control of the EMU and the correction of the single car; the software implementation of the control idea adopts a modular program design, and different modules realize corresponding functions. Combination can realize a variety of functions, broaden the scope of application of the control strategy; the control method of the controller can use fuzzy control, adaptive control, control, neural network control and other methods.

The advantage of the present invention is that: applying the EMU coordinated operation control strategy can realize the coordinated straight running and steering operations of the trackless wheeled hydraulic truck set in the underground roadway, and can be expanded to manual remote driving or unmanned automatic driving. The control strategy solves the problem that the personnel in the roadway cannot accurately control the hydraulic transport vehicles, avoids the safety risks caused by manual operation of hydraulic trucks, and can complete the operation of multi-vehicle groups following the vehicle in front, which is a good solution The driving problem of hydraulic trucks in underground roadways makes it possible for multi-vehicle groups to coordinate steering, improves the efficiency of underground mining, support and other heavy equipment transportation, and greatly increases the reliability of transportation.

Description of drawings

Fig. 1 is the schematic diagram of ultrasonic ranging sensor ranging;

Fig. 2 is a schematic diagram of the distribution of ultrasonic ranging sensors on a bicycle body;

Fig. 3 is a walking schematic diagram of an ultrasonic ranging system applied to a bicycle;

Fig. 4 is the schematic diagram of multi-vehicle group coordination operation applying described control strategy;

Figure 5 is an overall block diagram of the unmanned driving system;

Fig. 6 is a flow chart of the bicycle control strategy;

Fig. 7 Schematic diagram of single-workshop posture information transmission.

In the figure: 1-transmitter, 2-receiver, 3-roadway wall, 4-ultrasonic emission line, 5-ultrasonic reflection line, 6-car body, 7-traveling direction.

Detailed ways

1. Ultrasonic ranging system

As shown in Figure 1, the ultrasonic ranging sensor is composed of 1 transmitter and 2 receivers. The transmitter 1 emits an ultrasonic transmission line 4. When the ultrasonic ray touches the roadway wall 3, it will rebound, and the receiver 2 is used to receive Bounced ultrasonic rays. The round-trip time is the time when the ultrasonic wave sent from the ultrasonic transmitter propagates through the gas medium to the receiver. The round-trip time multiplied by the speed of sound in the gas medium is the distance traveled by the sound wave, and the measured distance is half of the distance traveled by the sound wave. This distance measurement method is a non-contact distance measurement with high sensitivity, which can collect distance information in real time and provide real-time and reliable information for the relative position judgment of the vehicle body. Since the ultrasonic wave propagates in the air, the speed is different at different temperatures, and the distance signal can be processed by using the temperature compensation method, so as to obtain more accurate distance information.

Figure 2 is a schematic diagram of the distribution of ultrasonic ranging sensors on a single vehicle body. The whole vehicle uses 8 ultrasonic distance measuring sensors. In order to meet the requirements of control, these distance measuring sensors are divided into two directions, front and rear. The first sensor is rear, left rear, and right rear respectively, and the L and R two sensors are left and right. Eight ultrasonic ranging sensors are distributed around the vehicle body, which can approximately measure the distance information from the edge of the vehicle body to the roadway wall within the horizontal 360° range of the vehicle platform centered on the vehicle body.

2. EMU coordinated operation control strategy

Fig. 3 is a schematic diagram of walking of the ultrasonic distance measuring system applied to a bicycle. In the state of going straight, 8 ultrasonic distance measuring sensors collect the distance value of the car body 6 to the roadway wall 3. Through control, the car body always walks along the center line of the roadway. Move around the centerline. 7 is the moving direction of the car body, and the front and rear marks of the 8 ultrasonic sensors are determined by the moving direction 7. The sensor ranging direction along the moving direction of the car body is the front sensor, otherwise it is the rear sensor.

Before the actual use of the present invention, the field is measured first, and the distance measurement value is corrected by a portable ultrasonic distance measurement device. In actual work, each sensor sets a threshold value according to the actual working conditions on site, and this value is a reference basis for judging the relative position of the car body and the roadway wall.

Figure 6 is a flow chart of the single vehicle control strategy. After determining the direction of motion of the car, the front and rear signs of the sensor are determined. SF, SFL, SFR, SL, SR are the distance values measured by the front, left front, right front, left and right sensors respectively. Take a bicycle as the first vehicle and autonomous driving as an example. As shown in the figure, first judge whether there is a wall in the front. If the measured value SF is less than the threshold value of the sensor, it indicates that there is a wall blocking the front. At this time, enter the steering mode; when it is smaller, judge again the absolute value of the difference between the left front distance and the right front distance |SFL-SFR|, when this value is greater than the threshold value, it means that the front and rear parts of the car body are too close to the wall. At this time, judge again which side the front part of the car is closest to. Attitude; when this value is less than the threshold value, it means that the front and rear parts of the car body still have a certain distance from the wall. At this time, the absolute value of the left and right distance difference |SL-SR| is judged. It is close to parallel to the roadway wall, but too close to one side wall. At this time, parallel movement is used to adjust the posture. If this value is less than the corresponding threshold value, it indicates that the car body is near the center line. At this time, keep the car body going straight.

Other situations can be generalized from the above situation. This control strategy can be applied to other vehicles other than the first vehicle after corresponding adjustment. After the distance information of the front vehicle is measured by the ultrasonic ranging system, it is processed by the single vehicle processor to become the pose information of the vehicle, and the information is uploaded to the bus. After the rear vehicle downloads the real-time attitude information of the front vehicle from the bus, the rear vehicle processor According to the set program, the vehicle will automatically follow the trajectory of the vehicle in front, and the distance between the two vehicles must be kept constant during the driving process. At this time, the movement of the vehicle needs to be independently adjusted by the single vehicle, as shown in Figure 5. After the control strategy is improved, it will correct the deviation of the rear vehicle, so that the rear vehicle can always maintain a certain distance to track the front vehicle, and will not scratch or hit the roadway wall due to deviation. After corresponding improvement, the control strategy can be adapted to single driving, manual remote driving and unmanned driving. According to this control strategy, the relative position between the car body and the roadway wall can be well judged. Due to the special structure of the hydraulic truck, it can realize special movements such as in-situ center steering, figure-of-eight steering, parallel left shift and right shift, so it can be controlled by the good handling of the hydraulic truck, so that the car body is always Keep moving on the centerline of the roadway and turn flexibly.

Fig. 4 is a schematic diagram of multi-vehicle group coordination operation applying the control strategy. The figure shows two situations of coordinated straight-going and coordinated turning. The invention can be applied to multi-vehicle series coordination operation. As shown in Figure 4, the connection between the two cars can be a hinge connection or a soft connection, that is, it is only connected by a steel wire or a soft mechanism. Since the distance between each car is controlled by the controller of the single car, the present invention The requirements for the connection between the two vehicles are not high, and the coordinated movement of the single workshop is controlled by the controller according to the program setting. The communication between single vehicles is completed by the CAN field bus. In this way, the multi-vehicle group is integrated into a whole. According to the system debugging, the multi-vehicle cooperative operation can be realized. The invention uses an open interface design, and the number of vehicles in the train group can be increased or decreased according to the needs of the operation, and the information of the entire train group can be observed and adjusted by a main controller (industrial computer or ordinary PC) , able to monitor the working status of the entire vehicle group in real time.

Figure 5 is an overall block diagram of the unmanned driving system. The hardware system of the present invention is divided into: an ultrasonic ranging system, a CAN field bus system, a central processing unit, a human-computer interaction system, an action execution system, and the like. The distance information between the car body and the roadway wall is collected in real time by the ultrasonic ranging system. The measured real-time data is calculated and converted into digital attitude signals by the single car controller and uploaded to the CAN bus system. The central processor is responsible for monitoring the working status of the entire system. At the same time, the exchange window of the control program of the entire train set is also on the central processing unit. The human-computer interaction interface is a communication platform for the EMU coordination operation system and engineering personnel. The system uses visual programming software, and engineers can The corresponding program modules are added or modified according to the actual situation, thereby increasing the adaptability of the EMU coordination operation system.

Fig. 7 is a schematic diagram of single workshop information transmission. The core idea of the control strategy described in this invention is that the attitude information of the vehicle in front can be obtained in real time, and the rear vehicle can adjust the actuators of the vehicle in real time after obtaining the real-time attitude information of the vehicle in front, so as to achieve the purpose of trajectory tracking and coordinated operations.

The invention of the invention can realize the coordinated operation of multi-vehicle groups of trackless wheeled hydraulic trucks in the underground, and the application of the invention can well implement the transportation operation of the hydraulic trucks in mines such as coal mines. The invention can adjust the automatic driving strategy through the human-computer interaction system according to the actual working conditions on site, thereby increasing the scope of application of the invention. The open design can connect multiple vehicles in series as a whole, and realize the collaborative operation of multiple vehicles according to the program of the system itself, so the invention has very good practical value. The control strategy can be applied to common hydraulic flatbed vehicles for multi-vehicle group cooperative operation after changing the system program according to the actual working conditions, and can also realize manned driving, manual remote control driving, and even unmanned driving of ordinary flatbed vehicle multi-vehicle groups, thereby improving the efficiency of the equipment. utilization rate. Therefore, the invention has broad application prospects in the industrial field.

Claims (5)

1. A control method for realizing coordinated operation of hydraulic truck multi-vehicle groups, characterized in that: (1) The hardware system includes ultrasonic ranging system, CAN field bus system, central processing unit, human-computer interaction system and execution system; (2) Use the ultrasonic ranging sensor to collect the distance information between the car body and the roadway wall in real time, so as to determine the relative positional relationship between the car body and the roadway wall; (3) The information measured by the vehicle in front through the ultrasonic ranging sensor is sent to the central processing unit, and the central processing unit calculates the vehicle body speed, steering angle, walking track and path relative to the roadway according to the set program. information, and upload the location information to the CAN bus system for the subsequent vehicles to call; (4) Each car in the EMU has an independent processor. The rear car processor downloads the attitude information of the front car from the CAN bus. According to the attitude information of the front car, the processor calculates and tracks the movement trajectory of the front car according to the control program. The required geometric parameters, and then determine the trajectory of the vehicle, to achieve the purpose of the rear vehicle automatically tracking the front vehicle, and the distance between the two vehicles remains constant during the tracking movement process; (5) Each car in the EMU is connected end to end to form a series system. The movement of the front car can be recognized by the rear car in real time. The rear car controls the movement of the car according to the attitude information of the front car, and the attitude information of the rear car is uploaded to the bus. system, so that the next car has motion reference information and realizes the coordination of multi-vehicle groups; (6) The processor of each car in the EMU, on the basis of tracking the movement trajectory of the preceding car, summarizes the distance information between the car body and the roadway wall measured by the ultrasonic ranging sensor of the car in real time, and each car in the EMU The hydraulic system of each vehicle includes a PLC control system. Through the independent control of the PLC controller in the hydraulic system of each vehicle, the attitude of the vehicle is adjusted to ensure that the rear vehicle does not scrape or collide with the roadway wall, and realize the automatic correction of the vehicle. 2. The control method for realizing the coordinated operation of multiple groups of hydraulic trucks according to claim 1, characterized in that: the central processing unit is an ordinary electronic computer or an industrial computer. 3. The control method for realizing the coordinated operation of multiple groups of hydraulic trucks according to claim 1, wherein the execution system is composed of hydraulic components of the hydraulic trucks. 4. The control method for realizing the coordinated operation of hydraulic truck multi-vehicle groups according to claim 1, wherein the ultrasonic ranging system is composed of ultrasonic sensors, temperature compensators, and A/D converters, and is used to monitor the vehicle body and the roadway. The wall distance is measured and the information is converted into an electrical signal. 5. The control method for realizing the coordinated operation of multiple groups of hydraulic trucks according to claim 4, characterized in that: the ultrasonic sensor is composed of a transmitter and a receiver, and the transmitter emits ultrasonic waves, which are received by the receiver after bouncing off the roadway wall , calculate the distance between the car and the wall according to the time difference between transmission and reception.

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