FEA Simulation of the Wheel legged Robot
FEA (Finite Element Analysis) simulation is a computerized method used to analyse the behaviour of structures or mechanical parts under different loading conditions. SolidWorks is a software that allows for FEA simulations to be performed on 3D models of mechanical parts and assemblies.
FEA simulation in SolidWorks involves breaking down the model into smaller finite elements, which are then analysed for deformation, stresses, and strains under various loading conditions. The results obtained from the simulation can be used to identify potential design issues or weaknesses, as well as to optimize the design to improve its performance and reliability.
The FEA simulation process in Solidworks typically involves several steps, including defining the geometry and material properties of the model, applying boundary conditions and loads, meshing the model, and running the simulation. The results of the simulation can then be visualized and analysed using various tools and techniques, such as stress plots, deformation plots, and animation.
FEA simulation in Solidworks is an essential tool for designers and engineers in the mechanical and manufacturing industries. It enables them to evaluate the performance of their designs before they are physically produced, saving time and costs associated with physical prototyping. Additionally, FEA simulations can help identify potential issues or weaknesses in a design, allowing for improvements to be made before the design is put into production. A wheel-legged biped robot can be made to function properly and be safe to operate by running FEA simulation in SolidWorks. For designers and engineers working in the mechanical and robotics fields, it is a useful tool.
The main links for the FEA simulation in Solidwork website is given below.
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Solidwork simulation - https://www.solidworks.com/product/solidworks-simulation
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Introduction to Solidwork simulation – Finite element analysis - https://blogs.solidworks.com/tech/2020/01/introduction-to-solidworks-simulation-finite-element-analysis.html
List of components
Main list of the components have categorised below to control the wheel biped robot to make the simulation in a realistic way:
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Battery: You will need a battery pack to power the robot. The type and size of the battery pack will depend on the power requirements of the motors and other electronics. Some common options include LiPo (Lithium Polymer) batteries or NiMH (Nickel Metal Hydride) batteries.
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Battery charger: A charger for the battery pack, to keep it charged and ready for use.
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Arduino board: This is a microcontroller board that acts as the brain of the robot. It receives input from the sensors and controls the motors and other components to make the robot move and perform its tasks.
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IMU (Inertial Measurement Unit): This is a sensor that measures the robot's orientation and movement in three-dimensional space. It typically includes accelerometers, gyroscopes, and magnetometers.
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Motor drivers: These are electronic components that control the direction and speed of the stepper motors and servo motors. They are typically connected to the Arduino board and receive signals from it to control the motors.
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Other electronics: Depending on the specific requirements of the robot, also may need other electronic components such as sensors, switches, or displays.
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Two Knee joints
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Two Shoulder joints
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Two wheels
The head controller/power is a critical component of the robot that provides the power and control signals to the motors and other electronics. The battery pack is particularly important, as it determines how long the robot can operate before needing a recharge.
Why Servo Motors
Servo motors are commonly used in wheel-legged biped robots because they offer precise control of the motor's position and speed. In these types of robots, precise control of the motor is critical for maintaining stability and controlling the robot's movement. Servo motors are designed to rotate to a specific position and hold that position with high accuracy. They also have built-in feedback mechanisms, such as encoders, that provide information on the motor's position and speed. This feedback information can be used in control algorithms, such as PID controllers, to adjust the motor's output and maintain stability.
Additionally, servo motors are often compact and lightweight, making them ideal for use in robots where space and weight are important considerations. They can also provide high torque output, which is essential for driving the wheels of the robot and providing the necessary propulsion. Servo motors offer precise control, feedback, compact size, and high torque output, making them an ideal choice for wheel-legged biped robots.
Difference between servo motors and stepper motors (Extra Details)
Stepper motors and servo motors are both types of electric motors that are commonly used in a wide range of applications. While they share some similarities, they have some fundamental differences in their design, operation, and performance.
Stepper motors are a type of motor that can rotate in small, precise steps. They are designed to move in precise increments, making them ideal for applications that require high precision and accuracy, such as robotics, 3D printers, and CNC machines. Stepper motors typically have a lower torque output than servo motors, but they can operate at lower speeds and with higher accuracy.
Servo motors, on the other hand, are designed to provide precise control over speed, position, and acceleration. They are commonly used in applications such as robotics, automation, and CNC machines, where precise control is critical. Servo motors use a closed-loop feedback system that allows them to detect and correct for errors in position and speed, making them highly accurate and reliable. They typically have a higher torque output than stepper motors, making them ideal for applications that require high force or acceleration.
The main difference between stepper motors and servo motors is how they control their motion. Stepper motors use an open-loop control system, which means that they do not have any feedback mechanism to monitor their position or speed. Instead, they rely on the number of steps taken to determine their position. Servo motors use a closed-loop control system, which means that they have a feedback mechanism to monitor their position and speed and can adjust their motion in real-time to maintain precise control.
In summary, stepper motors are ideal for applications that require precise, incremental movement, while servo motors are ideal for applications that require precise control over speed, position, and acceleration. Both types of motors have their own strengths and weaknesses and are selected based on the specific requirements of the application.
FEA
When it comes to selecting materials for FEA simulation of a wheel-legged biped robot in a realistic way, there are a few factors to consider:
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Strength: The material should be strong enough to withstand the forces and stresses that the robot will experience during its operation.
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Weight: The material should be lightweight so that it does not add unnecessary weight to the robot, which can impact its speed, agility, and energy consumption.
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Cost: The material should be cost-effective and readily available, so that it is feasible to use in the construction of the robot.
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Machinability: The material should be easy to work with and machine, so that it can be formed into the desired shapes and sizes for the various components of the robot.
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Corrosion resistance: Depending on the operating environment of the robot, it may be important to choose a material that is resistant to corrosion and other types of degradation.
Some common materials that are suitable for FEA simulation of robot components include aluminium, titanium, and carbon fibre composites. These materials are known for their strength, lightweight, and machinability. However, the final choice of material will depend on the specific requirements and constraints of the robot design, as well as the availability and cost of the materials.
The 1060 aluminium is used due to its light weight, high strength, and resistance to corrosion, aluminium alloys are frequently employed in robotics. In particular, 1060 aluminium alloy is a commercially pure aluminium alloy with superior electrical conductivity, strong corrosion resistance, and good forming capabilities.
The following are some justifications as to why the robot might be made of 1060 aluminium alloy:
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Lightweight: Compared to many other metals, the 1060 aluminium alloy has a density of only 2.7 g/cm3. Because of this, it is an excellent option for applications where weight is important, like in mobile robots.
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High strength: Cold working or strain hardening can still be used to strengthen the comparatively soft 1060 aluminium alloy. This can offer enough power for a variety of robotic applications.
Figure 40:Material properties for the Wheel legged biped robot
Figure 41: Displacement FEA for Head part
Figure 43: Stress FEA for Head part
Figure 45: Displacement FEA for Bone
Figure 47: Stress FEA for Bone
Figure 49: Displacement FEA for the joint
Figure 51: Stress FEA for the wheel
Figure 42: Strain FEA for Head part
Figure 44: Applied mesh for Bone
Figure 46: Strain FEA for Bone
Figure 48: Stress FEA for the joint
Figure 50: Displacement FEA for the wheel
Figure 52: Strain FEA for the wheel
Based on the FEA simulation results in Solidworks, which include displacement, stress, and strain analysis, the design of the wheel-legged biped robot is refined for optimal performance. These results allow the designer to identify areas of the robot that may be subject to high stress or strain, or areas where displacement may be a concern. By analysing and modifying the design based on these results, the designer can optimize the performance of the robot.
Once the design is refined in Solidworks, it is brought to Simulink using Simscape for further simulation. This simulation includes realistic dynamic modelling of the robot, allowing the designer to test and optimize its movement, stability, and control. By using the FEA simulation results as a basis for the design, the robot can be simulated with a high level of accuracy and reliability. The FEA simulation and subsequent simulation in Simscape allow the designer to create a robust and optimized design for the wheel-legged biped robot. By identifying and addressing potential areas of weakness, the robot can be designed to perform optimally, ensuring its success in real-world applications.