Stewart Platforms
Table of Contents
- 1. Simulink Project (link)
- 2. Stewart Platform Architecture Definition (link)
- 3. Simscape Model of the Stewart Platform (link)
- 4. Kinematic Analysis (link)
- 5. Identification of the Stewart Dynamics (link)
- 6. Active Damping (link)
- 7. Motion Control of the Stewart Platform (link)
- 8. Cubic Configuration (link)
The goal of this project is to provide a Matlab/Simscape Toolbox to study Stewart platforms.
The project is divided into several section listed below.
1 Simulink Project (link)
The project is managed with a Simulink Project. Such project is briefly presented here.
2 Stewart Platform Architecture Definition (link)
The way the Stewart Platform is defined here.
All the geometrical parameters are defined including:
- Definition of the location of the frames
- Location/orientation of the limbs
- Size/inertia of the platforms and the limbs
Other parameters are also defined such as:
- Stiffness and damping of the struts
- Rest position of the Stewart platform
3 Simscape Model of the Stewart Platform (link)
4 Kinematic Analysis (link)
From the defined geometry of the Stewart platform, we can perform static analysis such as:
- Jacobian Analysis that links the velocity of each limb to the velocity of the mobile platform
- Static Forces Analysis that links the forces applied by each limb to the resulting force/torque applied to the mobile platform
From the strut stiffness, we can also perform a Stiffness Analysis that consists of determining the Stiffness matrix and Compliance matrix of the Stewart platform from the geometry.
All these analysis are described here.
5 Identification of the Stewart Dynamics (link)
The Dynamics of the Stewart platform can be identified using the Simscape model.
It is possible to:
- Determine the dynamics from the actuators to the various sensors included in the Stewart platform
- Extract State Space models for further analysis / control synthesis
- Extract the Resonant Frequencies, Modal Damping, and associated Mode Shapes
The code that is used for identification is explained here.
6 Active Damping (link)
The use of different sensors are compared for active damping:
- Inertial Sensor in each strut
- Inertial Sensor fixed to the mobile platform
- Force Sensor in each strut
- Relative Motion Sensor in each strut
The result of the analysis is accessible here.