Robotics

Robotics

Introduction of Robotics

The main era of robotic research and development was the mid-20th century, primarily within an industrial environment where repetitive movements and lifting of heavy objects made the use of machines over humans attractive. Robots were mainly employed for tasks that were too dirty, distant, or dangerous for humans (Krebs and Volpe, 2013).

Joseph F. Engelberger and George Devol developed the first industrially used robot, the Unimate, in 1961. This was a hydraulically driven, programmable, 2-tonne robotic arm, adopted for automated die-casting. Engelberger had an interest in service robotics particularly in medical applications, and in 1984 he formed HelpMate Robotics. The HelpMate was used to transport medical supplies around a hospital.

In the late 1960s, Scheinman from Stanford University innovated the first successfully computer-controlled electrically powered robot arm – Stanford’s arm. The articulated arm had 6 degrees of freedom (DOFs) (Moran, 2007). Within the same decade, Stanford Research Institute developed the robot ‘Shakey’, equipped with a vision system and bump sensors. This was the first robot that used an artificial intelligence planner to gather images of its surrounding environment and apply this to map a route to a user-specified position. The robot was able to steer by differential control of its two drive motors and could navigate its way around halls, applying information it obtained from its route (Nilsson, 1984). Shakey could move at a speed of 2 meters per hour. The robot was known as Shakey because its mounted camera shook as the robot moved.

Concurrently, Stanford also began the development of the Stanford Cart, which was a remotely controlled, TV-equipped mobile robot. By 1979, the robot was able to successfully cross a room filled with chairs without any interference (Moravec, 1983). Also in the 1970s, ASEA IRB 6 was launched, which was the first robot to be electronically driven and controlled by the Intel 8008, one of their earliest microprocessors (Thiessen, 1981).

 

Robotic surgery experience

 

Robotics overcomes many of the disadvantages of open surgery as well as those still present with laparoscopy. In a way, it embodies the natural progression in the path to MIS. The advantages include 3D optics, wrist-like motion, tremor filtering, motion scaling, better ergonomics, and less fatigue. This translates into a lower conversion rate, decreased length of stay, easier learning curve, and the ability to operate in constricted spaces. Conversion from MIS to open has a deleterious impact on numerous patient factors, including increased transfusion rate (11.5% vs 1.9%), wound infection rate (23% vs 12%), complication rate (44% vs 21%), length of stay (+6 days vs base), and 5-year disease-free survival rate (40.2% vs 70.7%).

Recent analyses of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database comparing thousands of patients who underwent laparoscopic or robotic colorectal surgery found significantly lower conversion rates for robotics and lower length of hospital stay for both abdominal and pelvic robotic cases. There was no difference in postoperative complications when comparing the two groups and a significantly shorter length of stay for robotic procedures Other large database studies comparing the two groups with propensity score matching demonstrated reduced 30-day postoperative septic complications (2.3% vs 4%), hospital stay (mean: 4.8 vs 6.3 days), and discharge to another facility (3.5% vs 5.8%) in favor of robotic colectomy.

Analysis of the Michigan Surgical Quality Collaborative database comparing laparoscopic, hand-assisted laparoscopic, and robotic colon and rectal operations found significantly lower conversion rates for robotics in rectal resections (21.2% vs 7.8%), and approaching significance for colon resections (16.9% vs 9%). Conversion to open resulted in a significantly longer length of stay for robotic (1.3 days) and laparoscopic procedures (1.7 days).

Robotic inguinal hernia repair

Robotic inguinal hernia repair, performed as a transabdominal preperitoneal approach, has provided another minimally invasive approach in addition to laparoscopy. There has been a benefit demonstrated in obese patients for robotic compared to open inguinal hernia repair, with decreased postoperative complications. A multicenter retrospective chart review of 148 robotic and 113 open inguinal hernia repairs in obese patients identified a higher incidence of postoperative complications in open compared to robotic inguinal hernia repair patients (10.8% vs 3.2%, P=.047).

This same multicenter group identified in another study, where obesity was not defined as a variable, that robotic inguinal hernia repair still had a decreased incidence of postoperative complications compared to open repair (4.3% vs 7.7%, P=.047). An analysis of the National Surgical Quality Improvement Program database of 510 patients identified a longer operative time and cost with robotic, compared to laparoscopic and open inguinal hernia repair, in addition to a higher incidence of postoperative skin and soft tissue infection (2.9% robotic, 0% laparoscopic, and 0.5% open, P=.02).

Overall, robotic hernia repair is increasing in prevalence for ventral, inguinal, and TAR. Outcomes demonstrate that robotic hernia repair has an increased cost, but in more complex hernia repairs that are typically performed open, has the significant benefit of decreased length of stay. Conflicting data exist regarding surgical site infections, but the ability to primarily close the defect in ventral hernia repair has led to decreased surgical site occurrences, specifically seromas. Robotic hernia repair is safe overall and has demonstrated no significant safety or perioperative outcome differences from laparoscopic and open repairs in the literature thus far.

 

 Impact of Emerging Technology on Society

Robotic reliance in the business industry is an inevitable scenario. The use of robotic equipment to replace human involvement is an expanding area within the developed world. It is this innovative area that has seen the most significant action as it is proven that robotic replacements reduce the cost of human labor, eliminates human error, increases productivity, and ultimately achieves the ideal scenario of simultaneously increasing affordability and efficiency.

The global increase of operational robotic equipment has risen from 1.2 million in 2013 to 1.9 million in 2017. This shows a dramatic increase of approximately 700,000 machines over a 4-year period which is a staggering value since this technological advancement of robotics is still in its early stages. By further breakdown the countries which have invested and increased their robotic reliance are Japan, the United States, China, South Korea, and Germany, that is, the countries that have the greatest global presence and economic influence. Thus, due to these main countries taking the innovative path of robotic reliance, this sector is expected to be worth $67 billion by 2025, four times the estimated current market worth.

Moreover, this dramatic increase in technological advancements is due to positive business impact; however, it is not without an adverse effect on the workforce. Many of these technologically reliant businesses have economic stability without the need for a standard number of employees. This shows the innovativeness of robotics is reducing the need for traditional labor, eliminating jobs, and having consequences for the working class. Although evidence has shown that jobs are being taken away due to automation operation, simultaneously, new jobs are created. However, as the rate of job elimination is greater than job creation there is a concern that the use of robotics within our workforce may ultimately send the national economic stability into a downward spiral

 

Robotic Aspects

 

A level of programming there are many types of robots; they are used in many different environments and for many different uses. Although being very diverse in application and form, they all share three basic similarities when it comes to their construction:

  1. Robots all have some kind of mechanical construction, a frame, form, or shape designed to achieve a particular task. For example, a robot designed to travel across heavy dirt or mud might use caterpillar tracks. The mechanical aspect is mostly the creator’s solution to completing the assigned task and dealing with the physics of the environment around it. The form follows function.
  2. Robots have electrical components that power and control the machinery. For example, the robot with caterpillar tracks would need some kind of power to move the tracker treads. That power comes in the form of electricity, which will have to travel through a wire and originate from a battery, a basic electrical circuit. Even petrol powered machines that get their power mainly from petrol still require an electric current to start the combustion process which is why most petrol-powered machines like cars, have batteries. The electrical aspect of robots is used for movement (through motors), sensing (where electrical signals are used to measure things like heat, sound, position, and energy status) and operation (robots need some level of electrical energy supplied to their motors and sensors to activate and perform basic operations)
  3. All robots contain some level of computer programming A program is how a robot decides when or how to do something. In the caterpillar track example, a robot that needs to move across a muddy road may have the correct mechanical construction and receive the correct amount of power from its battery, but would not go anywhere without a program telling it to move. Programs are the essence of a robot, it could have excellent mechanical and electrical construction, but if its program is poorly constructed its performance will be very poor (or it may not perform at all). There are three different types of robotic programs: remote control, artificial intelligence, and hybrid. A robot with remote control programing has a preexisting set of commands that it will only perform if and when it receives a signal from a control source, typically a human being with remote control. It is perhaps more appropriate to view devices controlled primarily by human commands as falling in the discipline of automation rather than robotics. Robots that use artificial intelligence interact with their environment on their own without a control source, and can determine reactions to objects and problems they encounter using their preexisting programming. A hybrid is a form of programming that incorporates both AI and RC functions.

 

Application

As more and more robots are designed for specific tasks this method of classification becomes more relevant. For example, many robots are designed for assembly work, which may not be readily adaptable for other applications. They are termed as “assembly robots”. For seam welding, some suppliers provide complete welding systems with the robot i.e. the welding equipment along with other material handling facilities like turntables, etc. as an integrated unit. Such an integrated robotic system is called a “welding robot” even though its discrete manipulator unit could be adapted to a variety of tasks. Some robots are specifically designed for heavy load manipulation, and are labeled as “heavy-duty robots”.

Current and potential applications include:

  1. Military robots.
  2. Industrial robots. Robots are increasingly used in manufacturing (since the 1960s). According to the Robotic Industries Association US data, in 2016 the automotive industry was the main customer of industrial robots with 52% of total sales. In the auto industry, they can amount for more than half of the “labor”. There are even “lights off” factories such as an IBM keyboard manufacturing factory in Texas that was fully automated as early as 2003.
  3. Cobots(collaborative robots).
  4. Construction robots. Construction robots can be separated into three types: traditional robots, robotic arm, and robotic exoskeleton.
  5. Agricultural robots(robots). The use of robots in agriculture is closely linked to the concept of AI-assisted precision agriculture and drone 1996-1998 research also proved that robots can perform a herding task.
  6. Medical robots of various types (such as da Vinci Surgical System and Hospi).
  7. Kitchen automation. Commercial examples of kitchen automation are Flippy (burgers), Zume Pizza (pizza), Cafe X (coffee), Mark Shakr (cocktails), Frobot (frozen yogurts), and Sally (salads). Home examples are Rotimatic(flatbreads baking) and Boris (dishwasher loading).
  8. Robot combat for sport – hobby or sports event where two or more robots fight in an arena to disable each other. This has developed from a hobby in the 1990s to several TV series worldwide.
  9. Cleanup of contaminated areas, such as toxic waste or nuclear facilities.
  10. Domestic robots.
  11. Nanorobots.
  12. Swarm robotics.
  13. Autonomous drones.
  14. Sports field line marking.

Components

Power source

At present, mostly (lead-acid) batteries are used as a power source. Many different types of batteries can be used as a power source for robots. They range from lead-acid batteries, which are safe and have relatively long shelf lives but are rather heavy compared to silver–cadmium batteries that are much smaller in volume and are currently much more expensive. Designing a battery-powered robot needs to take into account factors such as safety, cycle lifetime, and weight.

Generators, often some type of internal combustion engine, can also be used. However, such designs are often mechanically complex and need fuel, require heat dissipation, and are relatively heavy. A tether connecting the robot to a power supply would remove the power supply from the robot entirely. This has the advantage of saving weight and space by moving all power generation and storage components elsewhere. However, this design does come with the drawback of constantly having a cable connected to the robot, which can be difficult to manage. Potential power sources could be:

  • pneumatic(compressed gases)
  • Solar power(using the sun’s energy and converting it into electrical power)
  • hydraulics(liquids)
  • flywheel energy storage
  • organic garbage (through anaerobic digestion)
  • nuclear

 

Actuation

Actuators are the “muscles” of a robot, the parts which convert stored energy into movement. By far the most popular actuators are electric motors that rotate a wheel or gear, and linear actuators that control industrial robots in factories. There are some recent advances in alternative types of actuators, powered by electricity, chemicals, or compressed air.

 

Electric motors

The vast majority of robots use electric motors, often brushed and brushless DC motors in portable robots or AC motors in industrial robots and CNC machines. These motors are often preferred in systems with lighter loads, and where the predominant form of motion is rotational.

 

Linear actuators

Various types of linear actuators move in and out instead of spinning, and often have quicker direction changes, particularly when very large forces are needed such as with industrial robotics. They are typically powered by compressed and oxidized air (pneumatic actuator) or an oil (hydraulic actuator) Linear actuators can also be powered by electricity which usually consists of a motor and a leadscrew. Another common type is a mechanical linear actuator that is turned by hand, such as a rack and pinion on a car.

Series elastic actuators

A flexure is designed as part of the motor actuator, to improve safety and provide robust force control, energy efficiency, shock absorption (mechanical filtering) while reducing excessive wear on the transmission and other mechanical components. The resultant lower reflected inertia can improve safety when a robot is interacting with humans or during collisions. It has been used in various robots, particularly advanced manufacturing robots and walking humanoid robots.

 

Air muscles

Pneumatic artificial muscles, also known as air muscles, are special tubes that expand(typically up to 40%) when air is forced inside them. They are used in some robot applications.

Muscle wire

Muscle wire, also known as shape memory alloy, Nitinol® or Flexinol® wire, is a material which contracts (under 5%) when electricity is applied. They have been used for some small robot applications.

Control

 

The mechanical structure of a robot must be controlled to perform tasks. The control of a robot involves three distinct phases – perception, processing, and action (robotic paradigms). Sensors give information about the environment or the robot itself (e.g. the position of its joints or its end effector). This information is then processed to be stored or transmitted and to calculate the appropriate signals to the actuators (motors) which move the mechanical.

The processing phase can range in complexity. At a reactive level, it may translate raw sensor information directly into actuator commands. Sensor fusion may first be used to estimate parameters of interest (e.g. the position of the robot’s gripper) from noisy sensor data. An immediate task (such as moving the gripper in a certain direction) is inferred from these estimates. Techniques from control theory convert the task into commands that drive the actuators.

At longer time scales or with more sophisticated tasks, the robot may need to build and reason with a “cognitive” model. Cognitive models try to represent the robot, the world, and how they interact. Pattern recognition and computer vision can be used to track objects. Mapping techniques can be used to build maps of the world. Finally, motion planning and other artificial intelligence techniques may be used to figure out how to act. For example, a planner may figure out how to achieve a task without hitting obstacles, falling over, etc.

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