Sunday, May 19, 2013

Recent Advances in Industrial Robots and Their Implications on Manufacturing

Industrial robots (e.g., ABB, PUMA) have been quite successful in mass production assembly lines. For example, they are routinely used to weld, paint, and join parts in automobile industry. However, small and medium manufacturers (SMM) in the US have largely stayed away from using industrial robots. They continue to rely on manual labor and this makes it hard for them to compete with overseas suppliers with low labor costs.

The National Association of Manufacturers (NAM) defines small manufacturers as companies with 500 or fewer employees and medium-sized manufacturers as companies with 2,500 or fewer employees. The NAM estimates that that the US has close to 300,000 SMM, representing a very important segment of the manufacturing sector. As we move towards shorter product life cycles and customized products, the future of manufacturing in the US will depend upon the ability of SMM to remain cost competitive.

This blog post explores the reasons behind the lack of adoption of industrial robotics technology by SMM and recent advances in robotics that might change the status quo.

Let us explore a representative scenario to understand the limitations of the current industrial robots and why they are not used by SMM. Imagine that you are working in a small company and building a prototype of new medical device. You are under extreme time pressure to meet an important deadline. As you are assembling the device, you realize the bracket is too compliant. You need to laser cut it again in a much stiffer material. The good news is that it will only take six minutes to cut the bracket. But the logistics associated with it will take an hour. You really need to continue assembling the rest of the assembly and testing the controller. You simply don’t have an hour to spend and can certainly use an assistant right now!

Here is what you would like your assistant to do - walk over to the material storage area, locate the right material, pick up the material, take it to the laser cutter, open the laser cutter, place the material in it, press the button to start cutting, wait for the part to finish, open the laser cutter, pick up the part, clean it, and bring it to you. Obviously human assistants can do all of these tasks without even flexing their cognitive muscles. I am sure that they can do all of these tasks while texting and surfing the net on their smart phones! Unfortunately the current industrial robots simply cannot do these tasks. So you simply cannot get a robot assistant today!

Robots that rule the assembly line have the following four limitations. First, they are immobile. They cannot go to the task location. The work has to be brought to them. Second, their dexterity is extremely limited. Simple tasks such as opening shelves and precisely placing and securing a previously unseen part in a machine are out of their capabilities. Third, it takes a long time to program them. So using robots on no-repetitive tasks is simply counter-productive. Finally, robots cannot work in the close proximity of humans because of safety concerns. So you can forget about a robot assistant walking over and handing you a tool or a part to assist you on the shop floor.

Most SMM use highly automated machines (e.g., CNC machines, laser cutter, water-jet cutters, CNC press-brakes, 3D printers). However, SMM shop floors tend to be unstructured and often go through changes to meet the needs of the projects at hand. Main sources of manual labor in SMM are material transport and handling, machine setup and calibration, inspection, clean-up, and packaging. Unfortunately, the current industrial robots that are designed for mass production assembly lines are of not much use in these tasks. So industrial robots offer very little value to SMM!

Recent advances in robotics are challenging the status quo and aiming to turn robots into important tools for SMM. I would like to share the following important trends:

  • Mobile manipulators are robots that can transport themselves to the work site. I recently saw demonstrations of mobile manipulators developed by Kuka that show impressive capabilities. This capability will be very useful in expanding the role of robots in manufacturing, particularly from the SMM point of view.
  • Dexterity has been a major obstacle to the widespread use of robots in manufacturing. Recent developments on robot hands are targeting to overcome this obstacle (e.g., Schunk and Barrett hands). 3D printing enables users to quickly create their own customized grippers in few hours.
  • Baxter from Rethink Robotics is aiming to eliminate the need for writing code to program robots. Instead, robots can be programmed by demonstrating the tasks. This is expected to empower workers on the shop floor. They will be able to start utilizing robots without the need to wait for a robot programmer to assist them.
  • Recent advances in human-safe robots are enabling robots to work in the close proximity of humans. Kuka lightweight arm and Baxter are representative examples of advances in this area. Many researchers are developing methods to track human operators in the workspace to make robots aware of humans in the workspace and change planned robot motions to avert injury to humans. For example, +Krishnanand Kaipa , +Carlos Morato , and +Boxuan Zhao  in my lab have developed a system to monitor a human operator working in the close proximity of a robot using four Microsoft Kinect sensors. This information is used by the robot to update its plan. The video of this system is shown below.

I believe that ultimately the convergence of the above mentioned technologies will create the second generation of industrial robots that will revolutionize the manufacturing industry. 

Once the demand increases for these robots, the cost for them will start coming down. There is no reason why low-end industrial robots cannot be sold for less than ten thousand dollars once the economy of scale kicks in. This in turn will make robots affordable for SMM and manufacturing cost-competitive in high wage countries.


  1. Safe human-robot interaction will also help us to deploy robots for house-hold activities.

  2. Two of the main challenges in my opinion are:
    1) High upfront setup cost to deploy a robot in a SMM shop. The high setup cost makes it more economical for the SMM to use manual labor instead of a robot.
    2) Mean times between maintenance/failure comes as the cost to high dexterity. Robots are fairly reliable when they are doing the same task over and over again. e.g. a parallel jaw gripper works well to grab objects of the same type over and over again (million+ cycles in the industry standard). However the cycle times for more dexterous hands (with three or more fingers) is as much as an order of magnitude lower.

    1. These are definitely some of the primary challenges in the field. Thank you for bringing them up. I would like to share some points:

      * Baxter from Rethink Robotics is a step toward addressing the first challenge. At a price point of $25K, as against a price range of $100 to $150K of traditional industrial robots, this adaptive manufacturing robot is primely set to change the game rules in the SMM sector.

      * Research in human robot collaboration (HRC) addresses the second challenge by answering questions of how to achieve physically tight/close collaborations between a robot and a human during assembly tasks and how to dynamically/adaptively distribute assembly operations between them depending on what each partner can do best in a particular context.

  3. I agree that the utilization of robotics will be a critical step for the future survival of small- and medium-sized manufacturing. From my perspective, one of the biggest barriers to more widespread deployment of robotics in SMM is one of "education." This goes beyond just learning how to use robots. It includes educating the general public about the benefits and risks associated with integrating robotics. There are many myths and outdated truisms that may dissuade adoption of robot technologies when it would be of significant use, and yet many others that oversell the capabilities of robotics. Education also includes informing new generations of manufacturers the processes of integrating and retasking robotics, and vendors to address the needs and capabilities of SMM production lines. It also involves, as Arvind Ananthanarayanan mentioned, educating SMM shops about the true costs of robotics. Used (and still fully functional and reliable) robots can be purchased for well under $10,000 US, but integrating robots into the factory floor can easily cost an order of magnitude more than that. I've seen people buy robots with the intention of automating tasks that are trivial for humans, and then give up in frustration with the sheer cost and effort necessary to even get the robots to perform seemingly basic functions.

  4. While most of the trends that would make robots an attractive option for SMEs have been pointed out in the blog, I would like to add more trend: making robots capable of following natural language instructions. This capability would provide a natural, intuitive, flexible, and safe mode of collaboration between the factory workers and robotic assistants.

  5. I would like to add a couple of exciting emerging technologies such as

    (1) universal manipulators that can hold objects of complex shapes and various surface properties (e.g., Hod Lipson's recent robotic gripper, see Brown, Eric, et al. "Universal robotic gripper based on the jamming of granular material." Proceedings of the National Academy of Sciences 107.44 (2010): 18809-18814), and

    (2) distributed motion planning algorithms capable of predicting human paths and following social conventions for robots cooperating with each other and humans on assembly tasks in complex environments (e.g., see Knepper, Ross A., and Daniela Rus. "Pedestrian-inspired sampling-based multi-robot collision avoidance." IEEE RO-MAN, 2012.)