Soft Robotics and Flexible Structures for Robots.pptx

Soft Robotics and Flexible Elements manufacturing

1. Module 3 Components of Autonomous Robots, AI and Robot Integration, Robot Operating System, nodes, Topics, sensor fusion; Hardwares : sensors, actuators, controllers; Autonomous mobile robots: Wheeled Robots, Quadruped robots

2. Core Components of Autonomous Robots

3. Sensing (Perception Systems) : Types of Sensors : LiDAR, cameras, ultrasonic sensors, infrared, etc. Sensor Fusion : Integrating data from multiple sensors to create a cohesive view of the environment.

4. CONTENTS: Introduction History Components of LIDAR System Basic Working Principle LIDAR Platforms Types of LIDAR Applications Advantages / Disadvantages Conclusion / References

5. LIDAR: Acronym for Light Detection And Ranging (sometimes Light Imaging, Detection, And Ranging). The LASER system, employed for monitoring the nature of environment is called LIDAR. It is an active remote sensing technology that measures distance by illuminating a target with a laser and analyzing the reflected light. Similar to RADAR, but uses laser light pulses instead of radio waves. LIDAR uses ultraviolet rays , visible rays and near infrared rays to image object. By illuminating the target using laser beam ,a 3-D point cloud of the target and it’s surrounding can be generated. Three types of information can be obtained: Range to target (Topographic LIDAR, or Laser Altimetry) Chemical properties of target (Differential Absorption LIDAR) Velocity of target (Doppler LIDAR)

6. WHY LIDAR ? It is used for generating precise and directly geo-referenced spatial information. Lasers produce a coherent light source. It is Active sensor , do not require sunlight, they can be used either during the day or at night. LIDAR is popularly used as a technology used to make high resolution maps.

7. HISTORY OF LIDAR: In the 1930s first attempts were made to measure air density profiles in the upper atmosphere by determining the scattering intensity from searchlight beams . LIDAR originated in the early 1960s, shortly after the invention of the laser. combined laser-focused imaging with the ability to calculate distances by measuring the time for a signal to return using appropriate sensors and data acquisition electronics.  Its first applications came in meteorology, where the National Center for Atmospheric Research used it to measure  clouds. The general public became aware of the accuracy and usefulness of LIDAR systems in 1971 during the Apollo 15 mission, when astronauts used a laser altimeter to map the surface of the moon. 1995 - First commercial airborne LIDAR systems developed.

8. Components of LIDAR System: Component of lidar system-LASER : Frequency : 50,000 (50k) to 200,000 (200k) pulses per second (Hz) (slower for bathymetry) Wavelength : Infrared (1500 – 2000 nm) for meteorology Near-infrared (1040 - 1060 nm) for terrestrial mapping Blue-green (500 – 600 nm) for bathymetry LIDAR Transceiver - Generates laser beam and captures laser energy scattered/reflected from target. Scanner - A laser scanner has three sub-components: the opto mechanical scanner, the ranging unit, and the control processing unit

9. Components of LIDAR System: POS(IMU & GPS) - Measures “sensor” position and orientation, Inertial measurement systems also contain accelerometers to measure the velocity. Operator - Permits operator interaction (control/monitor) with system Data storage - Captures all AIRBORNE system data required for generation of x , y , z “target” coordinates. Computer - Integrates/controls interaction of all of the above.

10. Components of LIDAR System:

11. Working Principle: Laser generates an optical pulse. Pulse is transmitted , reflected and returned to the receiver. This return beam/pulse is collected and processed to obtain property of target. Receiver accurately measures the travel time. X,Y,Z coordinates can be computed from 1. Laser range 2. Laser scan angle 3. Absolute location of sensor

12. Working Principle: Calculate Distance :- Distance=(Speed of Light * Time of flight) / 2

13. Working Principle: Physical picture in LIDAR remote sensing:

14. LIDAR Platforms: AERIAL/AVIATION(Airborne) - For highly detailed, local elevation data - Small area where high density is needed SATELLITE(space borne) - covers large areas with less detail TERRESTRIAL(ground spaced)

15. AERIAL/AVIATION platform: Used for topographic mapping and engineering application. It has 3 sub parts: Laser scanning Fixed wing platform Rotary wing platform

16. SATELLITE(space borne): Mapping of remote areas for scientific purpose. It has 3 sub parts: Geostationary Polar Sun synchronous

17. TERRESTRIAL(ground spaced): Produce detailed 3D models of buildings, bridges, streetscapes, factories and other man-made infrastructure. It has 3 sub types Short range Medium range Long range

18. Bathymetric Mapping System: Bathymetry is the study of underwater depth of lake or ocean floors. In other words, bathymetry is the underwater equivalent to hypsometry or topography. It uses blue-green laser that can penetrate water and provide returns of underwater objects or bottom. Effective collection of near shore bathymetry.

19. Types of LIDAR: ELASTIC LIDAR Elastic backscatter LIDAR - Mie scattering -Rayleigh scattering INELASTIC LIDAR -Raman LIDAR -Differential absorption LIDAR(DIAL) -Doppler LIDAR

20. Applications: Agriculture : Create a Topographical map of the fields and reveals the slopes and sun exposure of the farm land. Autonomous vehicles : Autonomous vehicles use LIDAR for obstacle detection and avoidance to navigate safely through environments. Geology and soil science : ICE Sat (Ice, Cloud, and land Elevation Satellite). Law enforcement : LIDAR speed guns Surveying, Transport , wind farm optimization and many more. Atmospheric Remote Sensing and Meteorology.

21. Present Technical Advancement in LIDAR: LIDAR speed gun- A LIDAR speed gun is a device used by the police for speed limit enforcement which uses LIDAR to detect the speed of a vehicle. Unlike Radar speed guns, which rely on Doppler shifts to measure the speed of a vehicle, these devices allow a police officer to measure the speed of an individual vehicle within a stream of traffic. Google driverless car- Google's robotic cars have about $150,000 in equipment including a $70,000 LIDAR (light radar) system. The range finder mounted on the top is a Velodyne 64-beam laser. This laser allows the vehicle to generate a detailed 3D map of its environment. The car then takes these generated maps and combines them with high resolution maps of the world, producing different types of data models that allow it to drive itself.

22. Google driverless car-

23. Advantages / Disadvantages of LIDAR Higher accuracy Fast acquisition and processing Acquisition of 1000 km2 in 12 hours. DEM generation of 1000 km2 in 24 hours. Minimum human dependence As most of the processes are automatic unlike photogrammetric, GPS or land surveying. Weather/Light independence Data collection independent of sun inclination and at night and slightly bad weather. Higher data density Up to 167,000 pulses per second. More than 24 points per Square meter can be measured. Multiple returns to collect data in 3D.

24. DISADVANTAGE: Inability to penetrate very dense canopy leads to elevation model error. Ineffective during heavy rain. High operational cost.

25. Conclusion: LIDAR mapping is a maturing technology in our country, and applications are still being identified and developed as end-users begin to work with the data. There are on-going initiatives to identify areas where the technology allows value-added products to be generated or where it offers significant cost reductions over traditional survey methods. LIDAR is unobtrusive and environmentally friendly, Unlike ground survey techniques. Airborne LIDAR can be flown over areas where access is limited, impossible, or undesirable.

26. References: [1] K. Thyagarajan and A.K. Ghatak, ‘Laser Theory and Application’ Macmillan Publication. [2] Dr. M.N. Avadhanulu & Dr. P.S. Hemne, ‘An Introduction to Laser Theory and Application’, S.CHAND Publication. [ 3] IEEE paper, ‘ Design concept for a global wind sensing lidar ’ DOI :  10.1109/JQE.1979.1070185 [4]Slide-share, ‘Introduction to LIDAR Technology’ https://www.slideshare.net/search/slideshow?searchfrom=header&q=lidar . [5]Wikipedia-Introduction to lidar - https://en.wikipedia.org/wiki/ Lidar