Pros And Cons Of Pneumatic Robots
Post By: Luke West On: 09-12-2022 Read Time: 5 minutes - Guides
Industrial robots aren’t a new concept, but they are an evolving one. Instead of clunky, mechanical metal arms, pneumatics are more frequently being chosen for operational control. This makes them generally safer, smoother and simpler to use. Newer types of composite materials also make them lighter and more manipulable, not to mention quieter.
Evolution Of The Industrial Robot
The first automated robot arm was deployed by General Motors in 1959 and revolutionised the automotive industry. Japanese manufacturing, in particular, took the idea to heart and automated many of their car factories using this technology. Over the new few decades, the first completely electric-driven robot was released, as well as the first robot controlled by a microprocessor. Industrial robot arms were developed for use in assembly lines, and were later designed to perform dedicated functions such as arc welding or paint spraying.
As with all early technology, pneumatic robots soon began to get smaller, with control mechanisms incorporated directly into the joints. Conversely, the robot arm’s capabilities expanded, so that the number of axes it could manipulate escalated. It got faster and was easier to control with a microchip. But robots were still expensive, complex and required safety fencing to protect human workers from injury.
After 70 years or so of evolution, we’re now looking at a whole new era of robot collaboration, with the spread of cobots or collaborative robots. Cobots, are a rapidly expanding industrial market, and pneumatics delivers the most sensitive and flexible approach to their design. Cobots free human employees from tasks that are boring or particularly strenuous, making their working life easier, safer and ultimately more productive. Today’s industrial robots are designed with integrated safety functions and intuitive programming software.
How Pneumatics Powers A Robotic Arm
Powering robotic arms involves four main steps.
- The compressor generates compressed air using another power source like electricity.
- This air goes to a reservoir, where it’s stored until needed. When the robotic arm is turned on, the system can function immediately using the stored air.
- The valves in each part of the arm determine how it moves, turning the air on and off in each section.
- The system actuators turn the compressor-generated potential energy into kinetic energy to operate the pneumatic arm.
Pros And Cons Of Pneumatic Robots
Pneumatic robot arms can be deployed in almost any industry, but they do have some drawbacks.
Pros
- Fluidity Of Movement
- Precision
- Temperature Resistance
- Less Maintenance
- Low Safety Risk
Fluidity Of Movement
Pneumatic robots are typically lightweight and compact. They can move pretty smoothly and with a minimum of noise. With pneumatic drives installed in individual joints, robotic arms can move through several different axes. This means an arm can raise, lower, swivel, retract, extend, etc. Compressed air components usually make less operational noise than similar mechanical parts.
Precision
Pneumatic robots can be programmed for extreme precision and accuracy, enabling them to be used in delicate applications like pharmaceuticals and surgery.
Temperature Resistance
Pneumatic robots are highly resistant to extremes of temperature. A pneumatic robot arm’s standard operating range is -40C to 120C.
Less Maintenance
With a good-quality air compressor, pneumatic robots generally require less maintenance than robots using some other form of actuation. Pneumatic grippers, for example, are controlled by vacuum and air pressure rather than hinges, which are more likely to wear out. Cleaning is simpler, with fewer moving parts. Maintenance is easier when repairing pneumatic arms than a more complex assembly. For example, it’s much easier to replace a pneumatic piston than to repair an electronic or mechanical system with lots of moving parts.
Low Safety Risk
Pneumatic robots pose less risk of explosion and fire. If a fault or failure occurs, only air can escape into the atmosphere, representing no environmental hazard. Fewer safety precautions are necessary, which may in turn speed up workflow. Safety sensors are also programmed into the newer generation of robots, which immediately vent the compressed air from the reservoirs if the arm encounters another object.
Cons
- Minimal Speed Control
- Prone To Moisture Build-Up And Damage
- High Operating Costs Long-Term
Minimal Speed Control
If you’re looking for precise tweaks of speed in your robot, pneumatic systems don’t compare well to other options like hydraulics or electrics. A typical pneumatic arm has only two settings – on and off.
Prone To Moisture Build-Up
One of the biggest problems with pneumatic systems is condensation, which can greatly reduce your equipment’s useful lifespan. The inlet air pressure and humidity can contribute to the probability of trapped moisture inside pneumatic pipes. This will very probably compromise the robot’s functionality and lifespan. Also, the bigger the pipe diameter and the higher the pressure, the more the condensation will increase. Experts recommend using the lowest possible pressure and the smallest possible pipes.
Some people install air dryers to dehumidify the compressed air before it goes into the pneumatic system. This may help, but doesn’t always eradicate the problem, especially in small actuators. An alternative is to use materials such as copper for your pipes. This has high thermal conductivity, which also helps to reduce moisture build-up.
High Operating Costs Long-Term
Pneumatic robots may be cheaper to buy than other systems, such as hydraulics. Pneumatic robot designs tend to use relatively affordable materials, like zinc, aluminium or plastics. Pneumatic systems still require lubrication to work efficiently, however, and may need a filter-regulator-lubricator unit to function optimally. Over the long term, pneumatic robots cost a lot more to operate because they’re less efficient.
Pneumatic Robots: Are They Worth It For You?
Robotic arms are useful for boring or dangerous tasks like material handling or removal, manufacturing assembly lines, welding and computer manufacturing. They may be deployed for automatic crop harvesting. Pneumatic robotic arms can also be used in medicine for making prosthetics and orthotics, and as surgical assistants.
Like anything else, you have to weigh up the pros and cons of pneumatic robots before you decide to invest. It’s important to be sure they’re appropriate for your application, and to figure out whether your process would work best with a compressed air system.
