Mecharithm Lessons

Upper-limb Rehabilitation Robotics

Upper-limb Rehabilitation Robotics

You may have already heard about rehabilitation, or you may have used some of the services in the past, or the first thing that comes to your mind is Britney Spears. But whatever you've already had in your mind, rehabilitation refers to enhancing or restoring the movement and quality of life for people with disabilities or other impairments due to diseases or injury. By definition, rehabilitation refers to help restore movement and function to people with disabilities caused by diseases or injury. However, doing repetitive tasks for long periods of time is daunting and less intensive than needed for proper…
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Location-based Augmented Reality (AR) Using GPS

Location-based Augmented Reality (AR) Using GPS

In the previous lesson, we learned how to implement an AR scene with a 2D image as a marker, and also, we learned how to detect the ground and put the 3D model on the ground. In this lesson, you will learn about the implementation of an AR application using GPS coordinates from three satellites without using an image marker or ground detection. Watch the video below for the entire lesson: https://www.youtube.com/watch?v=9ltZuIJKLOI You can also watch more lessons about Virtual Reality (VR) and Augmented Reality (AR) in the link below (note that more lessons will be added in the future):…
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Augmented Reality (AR) Scene with 2D Image Marker and Ground Detection

Augmented Reality (AR) Scene with 2D Image Marker and Ground Detection

In this lesson, you will learn how to implement an AR scene with a 2D image as a marker and also learn how to detect the ground and put the 3D model on the ground without using an image marker as a 2D marker or any other marker: Watch the video below for the entire lesson: https://www.youtube.com/watch?v=GJYb5gbDgIY You can also watch more lessons about Virtual Reality (VR) and Augmented Reality (AR) in the link below (note that more lessons will be added in the future): https://www.mecharithm.com/category/virtual-reality-vr-and-augmented-reality-ar/ If you enjoyed this post, please consider contributing to help us with the website's…
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What is Augmented Reality (AR)?

What is Augmented Reality (AR)?

In the previous lesson on the series of lessons about Virtual Reality (VR) and Augmented Reality (AR), we became familiar with the concept of Virtual Reality. In this lesson, we'll learn about Augmented Reality (AR) and we will become familiar with different methods to implement it. Augmented reality is a new technology for displaying a virtual event or object in the real world. The 3D model appears in AR based on a spatial reference in the real world: a 2D image, an object, or part of the ground. AR usually runs on Android and iOS platforms. The application of AR…
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What Is Virtual Reality (VR)?

What Is Virtual Reality (VR)?

As you may have already heard, Virtual Reality (VR) and Augmented Reality (AR) have been two of the big market trends for the last five to six years. You may even have worked with some of the devices featuring these technologies, like when playing games with those special headsets. VR and AR have changed our perception and interaction with computers and with the environment around us. VR shows us new alternate universes, and AR superimposes data, images, and unique experiences on the world around us. VR and AR are also very important in robotics. VR and AR found their way…
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Homogeneous Transformation Matrices to Express Configurations in Robotics

Homogeneous Transformation Matrices to Express Configurations in Robotics

Up to this point, we have discussed orientations in robotics, and we have become familiarized with different representations to express orientations in robotics. In this lesson, we will start with configurations, and we will learn about homogeneous transformation matrices that are great tools to express configurations (both positions and orientations) in a compact matrix form. This lesson is part of the series of lessons on foundations necessary to express robot motions. For the full comprehension of the Fundamentals of Robot Motions and the necessary tools to represent the configurations, velocities, and forces causing the motion, please read the following lessons…
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Cayley-Rodrigues Parameters to Express Orientations in Robotics

Cayley-Rodrigues Parameters to Express Orientations in Robotics

In this lesson, we will become familiarized with another representation for orientations in robotics that is called Cayley-Rodrigues Parameters. Cayley-Rodrigues parameters provide local coordinates for SO(3). They are local coordinates because the representation is not singularity-free, and not all orientations can be expressed by them. However, they have properties that make them intriguing. This lesson is part of the series of lessons on foundations necessary to express robot motions. For the full comprehension of the Fundamentals of Robot Motions and the necessary tools to represent the configurations, velocities, and forces causing the motion, please read the following lessons (note that…
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Unit Quaternions to Express Orientations in Robotics

Unit Quaternions to Express Orientations in Robotics

In the lesson about the Exponential Coordinate Representation of the orientation, we saw that the logarithm could be numerically sensitive to small rotation angles ΞΈ because of the division by sinΞΈ. We also saw that all other three-parameter representations of SO(3), like Euler angles and roll-pitch-yaw angles, suffer from similar singularities in representation, and this means that the solution will not always exist for the inverse problem where we want to find a set of parameters for a given orientation. Therefore, an alternative representation of the orientation named Unit Quaternion is used that alleviates the singularity at the cost of…
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Other Explicit Representation for the Orientation in Robotics: Roll-Pitch-Yaw Angles

Other Explicit Representation for the Orientation in Robotics: Roll-Pitch-Yaw Angles

In the previous lesson, we learned about Euler Angles Representation which is one of the ways to explicitly represent an orientation. This lesson will continue with explicit ways to represent the orientation, and we will learn about Roll-Pitch-Yaw Angles. This lesson is part of the series of lessons on foundations necessary to express robot motions. For the full comprehension of the Fundamentals of Robot Motions and the necessary tools to represent the configurations, velocities, and forces causing the motion, please read the following lessons (note that more lessons will be added in the future): https://www.mecharithm.com/category/fundamentals-of-robotics/fundamentals-of-robot-motions/ Also, reading some lessons from the…
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Other Explicit Representation for the Orientation in Robotics: Euler Angles

Other Explicit Representation for the Orientation in Robotics: Euler Angles

In the lesson about the degrees of freedom of a robot, we learned that there are at least three independent parameters needed to express the orientation of a rigid body. In the previous lesson, we learned about the exponential coordinate representation for the orientation that is a three-parameter representation for a rotation matrix R and parameterizes the rotation matrix using a unit axis of rotation and the angle of rotation about this axis. There are also other explicit representations that are useful in different applications when dealing with orientations. In this lesson, we will talk about Euler Angles and will…
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