Robotics

Tuesday, 27 March, 2018

Robotics is a domain in artificial intelligence that deals with the study of creating intelligent and efficient robots. Robotics is a branch of AI, which is composed of Electrical Engineering, Mechanical Engineering, and Computer Science for designing, construction, and application of robots.

What are Robots?
Robots are the artificial agents acting in real world environment. A robot is a machine especially one programmable by a computer— capable of carrying out a complex series of actions automatically. Robots can be guided by an external control device or the control may be embedded within. Robots may be constructed to take on human form but most robots are machines designed to perform a task with no regard to how they look.

Objective
Robots are aimed at manipulating the objects by perceiving, picking, moving, modifying the physical properties of object, destroying it, or to have an effect thereby freeing manpower from doing repetitive functions without getting bored, distracted, or exhausted.

Aspects of Robotics
The robots have mechanical construction, form, or shape designed to accomplish a
• Particular task. They have electrical components which power and control the machinery.
• They contain some level of computer program that determines what, when and how a robot does something.
Robot Locomotion
Locomotion is the mechanism that makes a robot capable of moving in its environment. There are various types of locomotions:
• Wheeled
• Combination of Legged and Wheeled Locomotion
• Tracked slip/skid

Legged Locomotion
This type of locomotion consumes more power while demonstrating walk, jump, trot, hop, climb up or down, etc.
It requires more number of motors to accomplish a movement. It is suited for roughas well as smooth terrain where irregular or too smooth surface makes it consume more power for a wheeled locomotion. It is little difficult to implement because of stability issues.
It comes with the variety of one, two, four, and six legs. If a robot has multiple legs then leg coordination is necessary for locomotion.
Legged locomotion is one of the most important but also one of the hardest control problems in humanoid robotics and none of the current approaches completely solves it to date. As it is obvious from studies of humans and animals, learning plays a significant role in both the balance stabilization and gait generation of biological legged creatures. It is therefore both an important application as well as an essential problem for learning control.
The total number of possible gaits (a periodic sequence of lift and release events for each of the total legs) a robot can travel depends upon the number of its legs.
If a robot has k legs, then the number of possible events N = (2k-1)!.
In case of a two-legged robot (k=2), the number of possible events is N = (2k-1)! = (2*2-1)! = 3! = 6.
Hence there are six possible different events
Lifting the Left leg
Releasing the Left leg
Lifting the Right leg
Releasing the Right leg
Lifting both the legs together
Releasing both the legs together
In case of k=6 legs, there are 39916800 possible events. Hence the complexity of robots is directly proportional to the number of legs.


Wheeled Locomotion
It requires fewer number of motors to accomplish a movement. It is little easy to implement as there are less stability issues in case of more number of wheels. It is power efficient as compared to legged locomotion.
Standard wheel: Rotates around the wheel axle and around the contact
• Castor wheel: Rotates around the wheel axle and the offset steering joint
• Swedish 45° and Swedish 90° wheels: Omni-wheel, rotates around the contact
• point, around the wheel axle, and around the rollers. Ball or spherical wheel: Omnidirectional wheel, technically difficult to implement.

Slip/Skid Locomotion
In this type, the vehicles use tracks as in a tank. The robot is steered by moving the tracks with different speeds in the same or opposite direction. It offers stability because of large contact area of track and ground.
Skid-steer locomotion is commonly used on tracked vehicles such as tanks and bulldozers, but is also used on some four- and six-wheeled vehicles. On these vehicles, the wheels (or tracks) on each side can be driven at various speeds in forward and reverse (all wheels on a side are driven at the same rate). There is no explicit steering mechanism--as the name implies steering is accomplished by actuating each side at a different rate or in a different direction, causing the wheels or tracks to slip, or skid, on the ground.

Components of a Robot
Robots are constructed with the following −
• Power Supply – The robots are powered by batteries, solar power, hydraulic, or pneumatic power sources.
• Actuators – They convert energy into movement.
• Electric motors (AC/DC) – They are required for rotational movement.
• Pneumatic Air Muscles – They contract almost 40% when air is sucked in them.
• Muscle Wires – They contract by 5% when electric current is passed through them.
• Piezo Motors and Ultrasonic Motors − Best for industrial robots.
• Sensors – They provide knowledge of real time information on the task environment. Robots are equipped with vision sensors to be to compute the depth in the environment. A tactile sensor imitates the mechanical properties of touch receptors of human fingertips.

Computer Vision
This is a technology of AI with which the robots can see. The computer vision plays vital role in the domains of safety, security, health, access, and entertainment.
Computer vision automatically extracts, analyzes, and comprehends useful information from a single image or an array of images. This process involves development of algorithms to accomplish automatic visual comprehension.


Hardware of Computer Vision System
This involves −
• Power supply
• Image acquisition device such as camera
• a processor
• a software
• A display device for monitoring the system
• Accessories such as camera stands, cables, and connectors

Tasks of Computer Vision
• OCR – In the domain of computers, Optical Character Reader, a software to convert scanned documents into editable text, which accompanies a scanner.
• Face Detection − Many state-of-the-art cameras come with this feature, which enables to read the face and take the picture of that perfect expression. It is used to let a user access the software on correct match.
• Object Recognition − They are installed in supermarkets, cameras, high-end cars such as BMW, GM, and Volvo.
• Estimating Position − It is estimating position of an object with respect to camera as in position of tumor in human’s body.

Application Domains of Computer Vision
• Agriculture
• Autonomous vehicles
• Biometrics
• Character recognition
• Forensics, security, and surveillance
• Industrial quality inspection
• Face recognition
• Gesture analysis
• Geoscience
• Medical imagery
• Pollution monitoring
• Process control
• Remote sensing
• Robotics
• Transport

Applications of Robotics
The robotics has been instrumental in the various domains such as −
• Industries − Robots are used for handling material, cutting, welding, color coating, drilling, polishing, etc.
• Military − Autonomous robots can reach inaccessible and hazardous zones during war. A robot named Daksh, developed by Defense Research and Development Organization (DRDO), is in function to destroy life-threatening objects safely.
• Medicine – The robots are capable of carrying out hundreds of clinical tests simultaneously, rehabilitating permanently disabled people, and performing complex surgeries such as brain tumors.
• Exploration – The robot rock climbers used for space exploration, underwater drones used for ocean exploration are to name a few.
• Entertainment − Disney’s engineers have created hundreds of robots for movie making.

Conclusion
This contribution to the soft robotics toolkit aims at providing a first numerical software for modeling and control of soft-robot. This tool could be used by the community for design and control assistance of soft robots. The approach seeks to be generic and could be applied for various shape of soft robots and (for now) two types of actuators: cables (tendons) and pneumatics. The different steps followed to build a numerical model of a softrobots are described in a tutorial using an example of a soft gripper recently proposed in the community. Some additional examples are provided to show the other features of our software.

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Category: Technology

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