Crawl-E
Meet the spider robot Crawl-e, which has six legs that move just like a real spider! It has a smart sensor to spot, avoid obstacles, and explore independently to navigate independently. Watch your spider robot come to life by controlling its movements, making robotics both fun and exciting. With an app to control its movements, this robot turns learning about robotics into a hands-on adventure filled with exploration and fun!
CRAWL-e ANATOMY:
Hardware:
MECHANICAL:
1. Material:
The CRAWL-e robot's body is made from corrosion-resistant, powder-coated aluminum alloy Al 5052 with varying thickness - [1.5 knee and hip, 1.2 rest.]. This material was chosen for its enhanced durability, easy maintenance, and aesthetic appeal. It provides a lightweight yet strong structure, optimizing the robot's performance.
2. Body Shape:
CRAWL-e has an eight/infinity-shaped body with three legs positioned on each side. This design is chosen for its balance between simplicity and functionality.
Advantages: CRAWL-e has an eight/infinity-shaped body because it provides a stable base, maintaining balance well on flat surfaces. Its simplicity makes it easy to construct, maintain, and troubleshoot, and the shape offers ample space for electronic components, batteries, and sensors.
3. Leg Alignment:
Leg alignment or orientation refers to the arrangement and positioning of a robot's legs relative to its body. This symmetrical arrangement ensures balanced support and movement.
Why It's Important: Proper leg alignment in CRAWL-e ensures stability, even weight distribution for strength and endurance, and optimal mobility for navigating various terrains efficiently.
4. Degrees of Freedom:
Degrees of Freedom (DoF) refers to the different ways a robot's parts can move. In the context of a hexapod robot like CRAWL-e, each leg has 3 DoF providing the robot with the flexibility to perform a wide range of movements. . This means each leg can stretch out, bend, and rotate.
Why are Degrees of Freedom Important? With 18 DoF in total (3 DoF per leg for 6 legs), CRAWL-e can walk smoothly, climb over obstacles, and change direction easily. This flexibility allows the robot to navigate various terrains and handle different tasks efficiently.
How is it Implemented in CRAWL-e? The first servo allows the leg to extend and retract, adjusting the robot's reach. The second servo controls the bending motion, moving the leg up and down. The third servo enables the leg to rotate, helping the robot turn and change direction.
5. Stability - Center of Gravity and Weight Management:
The center of gravity (CoG) is the point where a robot's weight is evenly balanced. Weight management refers to how the robot handles its weight and any additional loads it carries.
Why is it Considered? Maintaining a low and centered CoG is crucial for stability, preventing the robot from tipping over. Effective weight management ensures that the robot remains balanced and moves smoothly across different surfaces.
How is it Important? A well-managed CoG allows CRAWL-e to move steadily and avoid falls, even on uneven terrain. Good weight management supports stability and enables the robot to perform tasks efficiently, adapting to various environments and carrying additional loads if needed.
ELECTRONICS:
MotherBoard:
CRAWL-e features an advanced Motherboard designed with an ESP32 microcontroller. It includes 4 GPIO ports for versatile control, four auxiliary cable ports for additional peripherals, and six jumper ports for customisation. This Motherboard is capable of managing both the operations and communication for Crawl-e with wireless capabilities. Currently CRAWL-e motherboard
Features of CRAWL-e’s MOTHERBOARD
| Category | Specification |
|---|---|
| PCB Name | PeeCee |
| Processor | ESP 32 S3 module |
| Memory | 4MB flash memory |
| Connectivity | Bluetooth, USB, Wi-fi |
| GPIO ports | 4 [all 4 exposed] |
| Auxiliary Ports | 4 |
| Jumper Ports | 6 |
Motor Specifications:
CRAWL-e utilizes advanced serial servos to power its movements. These servos are crucial for providing the precise and powerful movements needed for the robot to function effectively. They feature a clutch mechanism to enhance performance and protect against damage.
These advanced servos are integral to CRAWL-e's performance, providing the necessary power, precision, and durability to handle a wide range of tasks effectively
SERVO SPECIFICATION:
| Specification | Details |
|---|---|
| Type | Serial Servo |
| Quantity | 18 |
| Stall Torque | 35 Kgf-cm |
| Rated torque | 8 Kgf-cm |
| Weight (per motor) | |
| No Load Speed | 0.16 sec/60° |
| No Load Current | 200 mA |
| Stall current | less than 5A |
| Gear Type | Metal gear |
| Operating vol | 6 to 8.4 V |
| Mechanical Limit Angle | 300° |
| Control Resolution | 0.01-degree resolution |
| Payload Capacity | 25 Kg-cm |
| Dimensions | 20 x 40 x 40.5 |
Caution: These high-capacity Servo motors have moving parts that can create pinch points. Fingers or other body parts caught between moving components can cause injury. Always ensure that hands and other body parts are kept away from moving parts while the servo is operating.
Ultrasonic sensor:
An ultrasonic sensor is a device designed to measure the distance to an object by utilizing ultrasonic sound waves. By calculating the time interval between the emission of the sound wave and the reception of the echo, the sensor can accurately determine the distance to the object. Ultrasonic sensors are reliable and provide accurate distance measurements without being affected by lighting conditions.
| Specification | Range |
| Measuring Angle | 15 degree |
| Min Range | 2cm |
| Max Range | 4m |
| Working Frequency | 40Hz |
| Working Current | 15mA |
| Operating Voltage | DC 5V |
| Sensitivity | -65dB min |
Additional Plug-ins:
External plug-ins in CRAWL-e refer to the additional components that can be connected to the robot's Motherboard to enhance its functionality. These plug-ins include sensors, LEDs, and displays. The external plug-ins connect to specific ports on CRAWL-e’s custom-built Motherboard. These ports are strategically placed on the board to ensure easy access and efficient connectivity, allowing users to enhance and customize CRAWL-e's capabilities according to their needs.
Wireless Connectivity:
Wireless connectivity allows CRAWL-e to communicate and be controlled without physical cables, using wifi and Bluetooth wireless communication.
Features of Wireless Connectivity in CRAWL-e:
- Remote Control: CRAWL-e can be controlled remotely via an app called Plode, enabling users to operate the robot from a distance.
- Data Transmission: Wireless connectivity facilitates the transfer of data, allowing for real-time monitoring and updates.
Rechargeable Battery:
The rechargeable battery in CRAWL-e features a high capacity for extended operation, efficient energy consumption, and quick charging to minimize downtime. It includes safety features to prevent overcharging, overheating, and short-circuiting, ensuring reliable and safe use. Additionally, the battery is designed for longevity, capable of enduring numerous charge cycles for long-term usability.
| Component | Specification |
| Battery | Voltage: 12.6 V battery [3.7 Li-ion x 3]
Capacity: 2000 mah |
| Adapter | Output Voltage: 12.6V
Output Current: 2A |
Built-in IMU:
CRAWL-e's built-in IMU (Inertial Measurement Unit) detects motion and orientation by measuring linear acceleration and rotational velocity. This helps maintain stability and balance and assists in navigation by providing precise information on the robot's movements. The IMU ensures CRAWL-e can adapt to terrain changes and navigate effectively.
Software:
CRAWL-e can also be controlled using the in-house software Plode app. We can connect Crawl-e to the Plode App by using Bluetooth in case of an Android device or by using a USB C-type Cable in case you are connecting it to a PC.
Plode contains an inbuilt remote control for Zing which allows you to control the robot to move in different directions. It also contains a menu of pre-programmed actions which you can make Zing to perform. For eg. Attention, Left Kick, Right Kick, Dance etc.
Through Plode’s AI mode, Zing can respond to voice commands by performing actions based on the command.
There are various ways to control CRAWL-e through the Plode app:
- Joystick Option : *attach a link for the tutorials on how to use it or to the wiki page *
- Block Programming : Ideal for beginners, the block-based (add a link for block-based programming wiki on word block-based) interface in the Plode app lets users create programs by arranging visual blocks. This method is user-friendly and helps grasp basic programming concepts without writing code.
- Python Programming : For those with more programming experience, Python(Add link for plodes python wiki on word ‘python’) offers advanced control over Zing. This text-based language provides powerful tools for writing custom scripts and handling complex tasks.
- Sensor data Monitoring
- Customization Options
- Other Apps:
CRAWL-e can be connected using other apps besides Plode, such as Arduino IDE. These apps provide additional features and customization options, offering flexibility in controlling and programming CRAWL-e. Whether you prefer intuitive interfaces or advanced scripting capabilities, these apps allow you to optimize CRAWL-e's performance for various tasks.
FAQs:
1. Can the robot be programmed for autonomous operation?
Yes, the robot can be programmed for autonomous operation using various programming languages and platforms. Users can develop custom algorithms for tasks such as obstacle avoidance, path planning, and environmental interaction.
2. What sensors are included in the robot?
The robot is built using durable materials like Aluminium alloy with a powdered coating to prevent rusting for the frame and high-quality plastics for other components. Joints and moving parts are designed to withstand regular use, and electronic components are protected against dust and moisture.
3. How do I control the hexapod spider robot wirelessly?
The robot can be controlled wirelessly via a mobile app, a computer interface, or a dedicated remote controller. Users can send commands, adjust settings, and monitor the robot's status in real-time using these interfaces.
5. How does the built-in IMU enhance the robot's performance?
6. What processor does the robot use?
7. What wireless connectivity options are available?
8. What kind of maintenance does the robot require?
9. Why is modularity important in the design of the robot?
10.Why is a low center of gravity crucial for the robot?