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SENSOR TECHNOLOGY IN INDUSTRIAL ROBOTS Industrial robots - What sensor system do they need?

Jan 7, 2022

Robots, today, are accomplishing all types of tasks for automotive, electronics and industrial manufacturing companies. As the robotics revolution comes up, maximum manufacturers are realising that they need to construct exact and detailed sensing elements into robotic equipment to support them while dealing with the challenges on the factory floor. Industrial robots use a lot of sensors to attain excellent operation and control in industrial automation production methods. The sensors in a robot let it respond with its environment in a flexible way and cutting-edge sensing technology is raising robots’ IQ to new intensities. The Cover Story talks about the sensors included in industrial robots and how sensor technology is one of the most critically applied sciences for industrial robots. - Nitin Kumar Sinha, National Sales Manager, Leuze Electronic India

With technical advancement of Industrial IoT, Augmented Reality (AR), cloud computing and other technologies, global manufacturing organisations have created intelligent factories to realise automation, information and intelligent industrial production. Industrial robots, for example, will play a vital role in this smart manufacturing transformation.

An industrial robot is a mechanical device that performs tasks automatically. It can respond to human directions, run pre-programmed applications or function with Artificial Intelligence (AI). Furthermore, it can mitigate the consequences of the harsh climate on production, limit the usage of human resources, ensure worker safety & assist the business in reducing production costs & improving production efficiency while ensuring product quality. Industrial robots are one of the primary pillars of the smart factory. Robotic automation is a rapidly developing field of science. Industrial robots have become commonplace in companies all around the world in just a few decades.

Robots around the world and in India

According to a June 2019 analysis by Oxford Economics, the investment in number of robots in operation globally has tripled in the last two decades to $2.25 million. According to research analysis, trends indicate that the worldwide stock of robots will increase even faster in the next 20 years, reaching as many as 20 million by 2030 —14 million of which would be in China alone.

At present, India lags far behind: however, things may change rapidly. The automotive four-wheeler manufacturing sector, which is now experiencing a slump, is an excellent example. Firms that had begun to boost their robot density (robots per 10,000 people) in the mid-2000s have now simply opted not to rehire the majority of the short-term, rotating, low-skilled contract labour in the face of stagnation. According to a survey released on January 22, 2019 by the International Federation of Robotics, India’s automotive sector was the primary consumer for industrial robots, accounting for up to 62% of overall supply.

Sensor technology in robots

According to industry estimates, the global industrial robot sensor market will increase at a compound annual growth rate (CAGR) of over 8% by 2021. Conforming to another study, by 2027, the vision system market will be worth $5.7 billion and the force sensor market will be worth the $6.9 billion for robot sensing applications such as consumers & vehicles.

The Government of India has granted a ₹1.45 trillion incentive package by broadening the production linked incentive (PLI) initiative to 11 industrial sectors, with a particular emphasis for the car and automobile component industries. As part of its China exit programme, the Japanese government has set aside $221 million in rebates for Japanese enterprises to relocate to India and other territories. The French government has offered financial assistance to help enterprises overcome liquidity challenges through its State Guarantee scheme, which guarantees the repayment of certain qualified loans up to the value of $358 billion.

Sensor technology is one of the most critically applied sciences for industrial robots. It enables robots to navigate and detect environmental alterations and make accurate decisions in tricky situations, just like humans. For robots, particularly in industrial automation, sensors must correctly supply crucial data to achieve associated complex procedures. To secure reasonable control and operation in industrial automation processes, industrial robots employ a significant number of sensors. Collaborative robots, for example, have torque sensors and cameras. They not only equip with a greater perspective, but they also keep the workspace secure. So, what sensors are included in industrial robots as well?

Industrial robots are multi-degree-of-freedom machine devices that can perform numerous activities autonomously, depending on their power and control capabilities. Machines, sensing and control are the three major components. Six sub-systems constitute these three significant sections. They are as follows:

  • Parts included: The system of the mechanical structure comprises three parts – the body, the arm and the end manipulator. Each major piece has several degrees of freedom constituting a mechanical system. The arm comprises three parts – the upper arm, the lower arm and the wrist. The end manipulator is a crucial component that is attached to the wrist directly. It could be a two or multi-finger claw, a paint spray gun, a welding gun or something else.

  • Sensing system: The sensing system helps gather information about the robot’s internal and external environment, allowing it to increase its maneuverability, adaptability and intelligence

  • Robot-environment interaction system: A system that allows a robot to communicate and cooperate with gadgets in the outside world

  • Human-machine interaction (HMI) system: A Human-Machine Interaction (HMI) system is a device that allows humans to communicate with and control robots

  • Control system: A control system directs the robot’s actuator to perform the prescribed actions and functions based on the robot’s operation instruction program and the signal received from the sensor

Frequently utilised sensors in industrial robots

Two-dimensional visual sensors, three-dimensional visual sensors, force/torque sensors and collision detection sensors are the most often utilised sensors for industrial robots.

  • Two-dimensional vision sensor: This is a camera that can detect moving objects & locate parts on a conveyor belt, among other things. Many intelligent cameras can see parts and assist the robot in determining its position & the robot can then alter its mobility accordingly, based on the information obtained.

  • 3D vision sensor: The 3D vision system needs two cameras or laser scanners at different angles to identify the object’s third dimension. Part choosing and placement, for example, requires using 3D vision technology to identify things & build 3D images and the analysis & selection of the optimum picking strategy.

    If the vision sensor provides the robot with eyes, the force/torque sensor provides the robot with a touch sensation. The end effector force is perceived by the robot using force/torque sensors. In most circumstances, the force/torque sensor is placed between the robot and the fixture, allowing the robot to monitor all forces supplied back to the fixture. With force/torque sensors, applications like assembly, manual guidance, education and force limiting can be realised.

  • Collision detection sensor: This sensor is available in a variety of configurations, and its primary purpose is to offer a safe working environment for operators which collaborative robots require the most

Some sensors could be a tactile recognition system that detects pressure on a soft surface and provides messages to the robot to limit or stop its movement. Some sensors are incorporated within the robot itself. Accelerometer feedback is used by some companies, whereas others use current feedback. When the robot detects abnormal force in either situation, it will initiate an emergency stop to ensure safety.

Innovations successfully combined

The RSL 400 represents the latest generation of our safety laser scanners. Our decades of experience have resulted in a development that is technologically unique and features impressive performance, robustness and many clever functions. Certain areas on machinery, systems and vehicles must be monitored for safety reasons in order to protect people or prevent collisions. The RSL 400 takes care of this easily and efficiently. Thanks to its high operating range of 8.25 meters and a scanning angle of 270 degrees, it can monitor even large areas. Together with two protective functions, the RSL 400 is able to perform tasks that previously required two scanners. Many clever functions such as the integrated spirit level, the removable connection unit and the integrated display make commissioning and handling a breeze. Integration into industrial Ethernet networks via PROFIsafe/PROFINET is also supported.

Ident, vision and proximity sensors

Users don’t have it easy. They constantly have to meet the challenges of their application – from simple code reading to complex inspection tasks. Today’s market offers a multitude of different systems each providing an optimum solution. The question as to which technology to choose is enough to drive you to despair: bar code readers, smart cameras, vision systems.

Codes can basically be split up into two groups: the 1D bar code and 2D code. A laser-based bar code reader is sufficient to identify a 1D bar code, whereas camera-based readers are normally used for 2D codes. The LSIS 220 2D code reader from Leuze electronic is based on a global shutter CMOS sensor with which the rolling shutter effect (a position error in images which occurs with line-by-line and column-by-column photographic recordings) is avoided. In addition to 2D codes, the LSIS 220 code reader can also read 1D bar codes and stacked codes.omnidirectionally, both on stationary objects and moving objects. The resolution of the LSIS 220 camera chip has been optimised for applications with moving codes as analysis of large quantities of data would take too much time. Optics and illumination have been improved to make sure codes are in sharp focus even at the edges and to illuminate the field of view homogeneously. At the same time, a high depth of field is achieved. Typically these readers are used e.g. for reading codes in handling machines and automatic testing machines, in robot systems, in circuit board production technology or for tracking applications. The 2D code is also often used where a large amount of information needs to be stored in a very small space.

The evolution of robotic sensors

The emphasis in the Industry 4.0 era was on the integration of automation and informationisation. As key players in the automated production process, industrial robots directly impact the level of automation in the industry.

The robot control system is evolving to become more open. Robots have been more integrated into manufacturing applications due to technological advancements, such as the industrial Internet of Things, Big Data analysis and virtualisation.

The uses and requirements of robots are getting increasingly sophisticated and demanding as the complexity and precision of industrial goods continue to rise. Robotic sensors have advanced from simple photoelectric and touch switches to high-level tactile, acoustic and visual sensors. The original “pulse” communication method has also been replaced between the robot servo and control systems. With more effective communication and a larger amount of communication data, “direction” communication cables have been designed for various on-site busbars.

Image Gallery

  • Sensor technology enables robots to navigate and detect environmental alterations and make accurate decisions in tricky situations, just like humans

  • Vision system

  • RSL 400

  • Nitin Kumar Sinha

    National Sales Manager

    Leuze Electronic India

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