Smart tree-planting car based on Gizwits IoT platform

毛球大大

Smart tree-planting car based on Gizwits IoT platform [Copy link]

Introduction: Aiming at the problem of low efficiency of artificial tree planting, a fully self-service, efficient and intelligent tree planting vehicle is designed. The structural composition of the device is introduced, and the motion mechanism of the device is analyzed. The transmission components are structurally designed using SolidWorks 3D software.

The Bluetooth module is used to realize the information transmission and command sending of the planting process. The IoT smart cloud module can report the planting data to the cloud platform in real time. A device model prototype was made. The test results show that it takes about 8.45 seconds to complete the planting of a tree and about 73.85 seconds to complete the planting of a 10 m×10 m area. The device fully realizes the functions of automatic tree transportation, pit digging, tree removal, pit filling, and watering, laying the foundation for the research in the field of automatic tree planting.

1 Working principle of the device

Figure 1 shows the overall structure of the tree planting vehicle. When the tree planting area is determined, multiple tree planting vehicles can work in the area at the same time. Before work, the planting area of each vehicle is issued using the Gizwits IoT cloud platform. At this time, the tree planting vehicle moves forward to the predetermined area, and the drill bit uses the GPS positioning module to determine the tree planting location. The drill bit starts to move up and down along the optical axis, and controls the digging depth according to the type of tree to be planted, and digs the tree pit.

At the same time, the planetary gear tower drives the tree clamp to start rotating, and stops rotating when it reaches the top of the tree pit. The vehicle continues to move forward, and according to the pre-set tree distance, ensures that the tree clamped by the tree clamp is just above the dug pit. The electric push rod of the tree pusher moves horizontally, pushing the sapling to peel off the tree clamp, and under the restriction of the limit device, using the gravity of the tree and the bottom of the tree, it falls vertically into the pit.

When the tree falls, it blocks the infrared rays emitted by the laser transmitter. The receiver does not receive the infrared rays and transmits the information to the bulldozer via Bluetooth. The electric push rod starts to move horizontally. When the soil dug out by the drill is gathered back into the pit, the vertical electric push rod moves downward at the angle adjusted by the wedge block to achieve the function of compacting the soil. After the compaction is completed, the water pump is started to realize the watering function to ensure the survival of the seedlings.

Figure 1 Overall structure of the tree planting vehicle

During the process of transporting trees, lowering trees, compacting soil, and watering at the rear of the vehicle, the GPS positioning module has located and dug the next hole at the drill bit position at the front of the vehicle, and the tree-planting vehicle moves forward to repeat the tree-planting process. This simultaneous work greatly improves work efficiency. After each tree is planted, the IoT Gizwits Cloud module will return the remaining seedling information and the remaining water to the cloud platform. When the remaining seedlings and water are insufficient, an alarm signal will be issued and the tree-planting supply station will be returned for replenishment. When the remaining seedlings are insufficient and return to the supply station, the corresponding tree clamp moves to the opposite side of the tree-planting mechanical arm, the servo and solenoid valve receive the return signal, the solenoid valve is powered off, and the servo drives the crank connecting rod to move, opening the front limit device to facilitate the mechanical arm to climb the tree.

An image recognition camera is installed above the drill bit. The video can be uploaded to the Internet of Things. By using opencv to analyze the video and instantaneous pictures, information about the planting of saplings can be obtained, mainly including whether they are planted vertically and whether the soil is flattened. In order to accurately locate the hole dug by the drill bit, the GPS Beidou positioning module is used. The drill bit moves up and down to the pre-set position to dig a hole. The positioning of the sapling can return the location of the sapling planting in real time and return to the cloud platform. The planted areas and unplanted areas are marked on the tree planting map of the cloud platform, and the planting situation of the entire area can be clearly seen. At the same time, it is combined with 5G technology and the Internet of Things to achieve the concept of interconnection of all things. The overall monitoring and information transmission use Bluetooth modules and IoT Gizwits Cloud modules. The IoT part can exchange information with the mobile app in real time and report planting data to the cloud platform.

2. Device structure design

2.1 Planetary gear mechanism

The upper planetary gear drives the outer ring to realize the rotation of the **tree clamp. In order to solve the problem of entanglement of the wiring of the electronic control part during the rotation of the gear, the lower planetary gear is designed with a single-chip microcomputer that controls the movement of the battery valve and the servo. The two layers are connected by the two shafts of the motor to achieve synchronous rotation in the same direction. The sun gear is driven by the motor to rotate, and the sun gear drives the three planetary gears to rotate, and then drives the gear rack to rotate. Through this process, the circular motion of the tree clamp is realized, and the storage and transportation of seedlings are realized. The planetary gear is shown in Figure 2.

Figure 2 Schematic diagram of planetary gear transmission mechanism

2.2 Openable and closable electromagnetic limit rubber tree clamp

The rubber hook is used as a tree clamp, and the rubber wheel and rubber pad are used to fix the tree to achieve the function of stably clamping the tree. The three-sided limit device is designed to include a left-side limit device, a right-side limit device and a front limit device. During the falling process of the tree, the rebound collision with the limit device can effectively control the falling range of the tree. The left-side limit device is equipped with a door-opening servo, and the right-side limit device is equipped with an electromagnetic opening and closing device. The front limit device and the left-side limit device are connected to the door-opening servo by a crank connecting rod. The cooperation of the door-opening servo and the crank connecting rod realizes the opening of the front limit device. After opening, the robot arm can climb the tree. After the climbing process is completed, the front limit device is closed, and the electromagnetic opening and closing device absorbs the front limit device to realize the limiting function, as shown in Figure 3.

Figure 3 Openable and closable electromagnetic limit rubber tree clamp

2.3 Mutually perpendicular electric push rod bulldozer structure

At the appropriate height of the rear of the vehicle body, a group of electric push rods are set on the left and right to form a bulldozer device to ensure that the electric push rod can achieve the purpose of tamping when it is fully extended. Each group consists of two electric push rods connected vertically. A bulldozer device fixing block with an inclination angle of 30° is fixed under the horizontal electric push rod to ensure that the horizontal electric push rod can gather the soil dug around the tree. The top of the electric push rod perpendicular to the horizontal direction is connected to the tamping plate, which can self-adjust the angle of soil compaction according to the flatness of the soil, and move left and right, front and back at the same time to achieve the functions of soil gathering and compaction, as shown in Figure 4.

Figure 4 Mutually perpendicular electric push rod bulldozer structure

3 Design of electronic control scheme

The main control board uses the Arduino Nano control board, which is connected to peripherals such as the motor drive module, image recognition camera, GPS Beidou positioning module, electric push rod, spiral drill head, Gizwits IoT module, etc., and then collects information through sensors such as laser transmitters and receivers and water level detection modules to control the progress of each tree planting process.

The main control board determines the specific location of tree planting through the information collected by the GPS Beidou positioning module, so as to realize regional planting, which is convenient for multiple tree planting vehicles to work at the same time without interfering with each other. The video taken by the main control board through the image recognition camera can be uploaded to the Internet of Things. By using opencv to analyze the video and instantaneous pictures, information on the planting status of the seedlings can be obtained, mainly including whether they are planted vertically and whether the soil is flattened.

The main control board determines whether the sapling has been planted through the information returned by the laser transmitter and receiver, and decides the subsequent soil compaction operation. The electronic control design of the tree planting car is mainly divided into two parts: one part is the Bluetooth module to realize the information transmission of the planting process, send commands, etc.; the other part can report the planting data to the Gizwits IoT cloud platform in real time through the IoT Gizwits module. Figure 5 is the control block diagram of the tree planting car.

Figure 5 Control block diagram of the tree planting car

The project in this article adds the Internet of Things control function, as shown in Figure 6. Using ESP8266 as the medium, the node-red online tool is used to build an Internet of Things platform. The PC side serves as the main console to receive data fed back by various sensors to monitor the various indicators of the tree planting robot and ensure the normal operation of the robot.

Figure 6 IoT control block diagram

4 Experimental testing

Traditional tree planting machines can only focus on one link of tree planting and cannot truly achieve fully automated tree planting. Compared with large tree planting equipment, this tree planting vehicle has a reasonable design and achieves the goal of minimizing the size while ensuring complete functions. The combination of the Internet of Things and machine vision opencv ensures the complete reporting of tree planting process information, which facilitates timely adjustments when special circumstances occur.

Through analysis, a fully automatic, efficient and intelligent tree planting vehicle physical model was made as shown in Figure 7, with a size of 500 mm × 300 mm × 315 mm. The physical model was tested and the data are shown in Table 1. It takes an average of about 8.41 s to complete the planting of a tree, and an average of about 73.85 s to complete the planting of a 10 m × 10 m area of land. During the test, the planting process of the device was smooth.

Figure 7 Physical model

Table 1 Experimental test data

5 Summary

The device can combine planting, automatic tree transport, automatic pit digging, automatic tree removal, automatic pit filling and automatic watering, truly freeing hands and automating tree planting. After the previous series of work is completed, the water tank sprays water to ensure the survival of the seedlings. The reasonable structural arrangement greatly improves the space utilization rate, and the front and back work at the same time, which improves the work efficiency and is suitable for mass production.