Utilizing Technology in Manual Material Handling and Safe Lifting
Industrial use of exoskeletons is just starting to be explored.
- By Mick Snyder
- Feb 01, 2016
Automation and robotics have made material handling effortless (aside from the headaches created by software glitches). However, there are major limitations and some tasks cannot be done with robots or are simply cost prohibitive. There are devices and technology available and soon to be available that alleviate these restrictions.
Intelligent Assist Devices (IADs)
Intelligent Assist Devices for lifting are not new, and the technology isn't cutting-edge any longer, but they still function better than numerous other alternatives. In terms of cost, they are much more attainable than installing a robot but still much higher than something like a lift table, but they are also way more functional. IADs are, in a sense, a hybrid between robotics and manual human lifting. They are basically high-tech small cranes that utilize sensors and attachments with much greater functionality and allow for extensive human interaction.
These devices use servo motors and microcontrollers to allow a user to directly guide, lift, push, or position objects with precision and speed, without the rough movements of traditional overhead or jib cranes. The IAD lifts with gentle movements and moves smoothly along with the user, giving the feel that the device is mimicking human motion. The movement of the IAD occurs using algorithms in the software to direct immediate movement so the operator does not notice any lapse in response time. Because an IAD is connected to a crane of some variety, it lifts 100 percent of the load, eliminating stresses from lifting on the human body.
The end effectors used for IADs utilize hooks, clamps, vacuum cups, magnets, expansion bulbs . . . if you can think of it, someone out there can build it. The end effector can be used to lift, lower, rotate, spin, press, grab, and release items—and it can do it without harsh movements and with the speed of human movement. They can be as large as an automobile or as small as a table-mount version.
The main drawback to IADs is that they are tied to a crane of some sort (either an articulating jib or an overhead crane is most typical), limiting where they can be utilized. For a manufacturing plant in an assembly area, these work great, but not for a health care setting such as a nursing home, where floor space is minimal and movement in and out of doorways is needed.
Where limitations of movement hold back the use of IADs, the newest versions of exoskeletons allow for complete mobility. An exoskeleton is a robotic-like device that is worn by the user and mimics human movement. Think of it as wrapping a robot around a human. It functions as a lift assist device by use of a mechanical advantage, allowing the user to lift heavy objects with little to no effort. Some of these exoskeletons are capable of allowing a person to lift more than 200 pounds with no additional force.
These are not the massive chunks of steel, cyborg-looking exoskeletons most people think of (some still are but are generally in R&D); most of these are streamlined exoskeletons with carbon fiber shells or body-hugging material covering structural braces, giving them an attractive and slim appearance. There are some soft exoskeleton devices also being introduced that have few rigid parts and utilize pneumatics and bladders, cables, or filaments to provide mechanical advantages or "power."
Exoskeletons range from backpack-style lift assisting devices to full-body assists for walking and lifting. Some engage via hand devices when a lift occurs, while others engage using sensors. Some are passive, not utilizing a power source, and others utilize batteries, hydraulics, and/or pneumatics.
While there are only a few currently available that function in industry, there are some being sold to consumers, while others are still in R&D. Rehabilitation exoskeletons and military units have been in use for several years, but industrial use is just starting to be explored.
One unit worn on the torso is designed specifically for manual lifting of boxes or something with a similar grip. This device redistributes part of the weight of the load to other portions of the body, predominantly the shoulders and legs. At the same time, it positions the back into a proper lifting position and holds 50-75 percent of the load’s weight.
Another torso device is similar to a harness but worn like a short-sleeve T-shirt and is designed to reduce fatigue when holding the arms out or overhead (such as when lifting/placing items above the waist or overhead work). It works by engaging when the arm is lifted above an adjustable threshold and then transfers the load on the arms from the shoulders to the core of the body.
These "hybrid" exoskeletons are about to transform how manual material handling is done and save the backs and shoulders of many workers due to lower costs and faster acceptability into the workforce.
There are a couple of passive exoskeletons that are zero load devices, meaning they carry the weight of the exoskeleton. These units also transfer the load on the arm to the ground, reducing the weight felt on the human body by 50 percent and allowing a person to hold a load at arm's length with little effort. Industries such as aerospace and shipbuilding have tested and are currently using these in manufacturing where the tool used can weigh in excess of 40 pounds.
Full-Featured Powered Exoskeletons
Sensors are being utilized on some of the most advanced exoskeletons. These detect electronic impulses from the wearer’s nervous system so that when the brain tells the leg to move, the exoskeleton moves right along with the leg, so there is zero lag time in moving and there are no control buttons to push for walking, bending, lifting, etc. This type of exoskeletons has great potential in health care fields for lifting patients, as well as in industry for lifting heavy items that are required to be moved by hand. These exoskeletons tend to be full-body or lower-body designs, most utilizing batteries stored in backpack or fanny-pack style compartments. These exoskeletons are all zero load, giving the device a weightless feel.
Lower body exoskeletons are being widely commercialized for the rehabilitation field, allowing paraplegic persons to walk, some for the first time ever. These exoskeletons show promise in industry for lifting, as well as reducing fatigue if carrying heavy objects is required. Combined with attachments, lower body exoskeletons could create the base for modular devices.
The Future . . .
There are companies that have designs in the R&D stage for units that are designed for disaster recovery and rescue that would allow humans to be fully protected from physical hazards such as fire, heat, sharp objects, and potentially even shrapnel. These "suits" also are being developed to protect against environmental hazards such as highly toxic atmospheres or high levels of radiation (think of them as high-tech Level A hazmat suits with air conditioning and a drinking fountain). These exoskeleton suits will not only protect the wearer from hazards, but also give them super-human strength to move minor wreckage; carry persons, tools, or excessive gear; as well as sustain work of longer duration with less fatigue.
There is great potential to decrease injuries with the use of these new technologies, especially musculoskeletal disorders and repetitive task-related injuries. Initial costs can be considerable for some of these units, but they are much cheaper than a back surgery. As with all technology, the first designs cost a small fortune, but as we are seeing even now, the pricing is decreasing and the quality is increasing for these devices.
In 30 years, we might all have flying cars like "Back to the Future II" predicted we would in 2015 or be able to figure out a tricorder like on "Star Trek"! For more information on exoskeletons, exoskeletonreport.com is a great resource.
This article originally appeared in the February 2016 issue of Occupational Health & Safety.