Скачать или смотреть Mini Tractor for Overhead Bridge Construction (Working Model)

Building a working model of a mini tractor specifically for overhead bridge construction is a fantastic engineering project. For this context, the tractor isn't just a vehicle; it's a segment launcher or a gantry carrier designed to navigate narrow beam paths.
Here is a breakdown of how to design and build this model.
1. Core Design Concept
In overhead bridge construction (especially segmental bridges), the "tractor" usually serves one of two purposes:
The Segment Hauler: Transports heavy concrete segments over the already completed portion of the bridge.
The Launching Gantry Support: Moves the massive crane structure forward.
Key Feature: To operate on an overhead bridge, the model needs a narrow wheelbase and high stability.
2. Materials & Components
To make it a "working" model, you’ll need a mix of structural and mechanical parts:
Structural
Chassis: Aluminum C-channels or thick PVC sheets for rigidity.
Wheels: Heavy-duty rubber wheels. Consider a multi-axle design (6 or 8 wheels) to mimic how real tractors distribute weight on bridge segments.
Mechanical & Control
Motors: High-torque geared DC motors (12V). You need power over speed.
Steering: A high-torque servo motor for precise navigation.
Microcontroller: Arduino Uno or ESP32 (if you want Bluetooth/Wi-Fi control).
Actuator: A linear actuator or a motorized winch if you want the tractor to actually lift or tilt segments.
3. Recommended Features for the Model
To make the model stand out, incorporate these construction-specific functions:
| Feature | Implementation |
|---|---|
| Crab Steering | Allow all wheels to turn in the same direction, enabling the tractor to move diagonally or align perfectly with bridge beams. |
| Load Bed | A flat, low-center-of-gravity platform to carry "concrete" blocks (made of wood or 3D-printed plastic). |
| Leveling System | Use an MPU6050 (Gyroscope) to keep the load level if the bridge model has an incline. |
| Safety Sensors | Ultrasonic sensors at the front and back to prevent the tractor from driving off the edge of the bridge. |
4. Building the "Overhead Bridge" Environment
The tractor needs a context to work in. Build a simple Beam Bridge section:
Piers: Use PVC pipes or wooden blocks.
Girders: Two parallel tracks (I-beams) that the tractor's wheels fit onto perfectly.
The "Gap": Leave a section of the bridge unfinished to demonstrate how the tractor delivers the next piece of the puzzle.
5. Basic Wiring Logic
If you are using an Arduino, the logic flow would look like this:
Input: Remote Control (Joystick) or Autonomous Sensors.
Processing: The Arduino calculates the speed and steering angle.
Output: The L298N Motor Driver sends power to the wheels, and the Servo