Why Robots Can’t Play HockeySaturday 21 July 2018
|| Why Robots Can’t Play Hockey, (or things to consider for your first robotics project.) by Tom Kurilovitch, AMS Senior Applications Engineer
|When my son was younger he really wanted to play hockey. We went out to get a pair of skates and quickly hit the rink to learn how to skate. He was so excited after his first week learning to skate that he told everybody ‘I am a hockey player now, I can skate!’. Well, a month later (and a fair amount of money) he was amazed at how much additional gear was required to ‘be a hockey player’.|
|As an industrial controls application engineer my customers always have process issues they want to solve. While we at AMS are always excited to help them out, many times the solution is not centered around a single product (like a pair of skates), but an array of products to implement a full solution (pads, helmet, stick, gloves, bag, etc.). The one product that is the most misleading is also the most sought after, Robots!|
|Robots are cool! In industrial automation they are fairly unique in that they install quickly, and with a few quick commands you can perform 90% of the process without much effort. Very satisfying for an industry where most timelines are measured in weeks or months. However, what is typically overlooked is the Robot is not the machine, a Robot is a component.|
|Many people new to robots have application ideas that they know can be completed using a robot (usually because AMS assisted with a robot simulation to test for reach and cycle time testing). Most customer are excited to purchase their new solution and implement without much thought into what else may be required. In most cases putting a robot on a table and pressing the ‘Go’ button is only the first step in feasibility testing, the final machine requires much more.|
|First thing to consider when looking at a robot system is the external controls required for reliable and safe operation. In all cases for a robot cell safety must be the first consideration; meaning light curtain, door switches, and e-stop buttons with potentially a safety controller. Also, any control of external components (pumps, valves, nest, rotary tables, loading/unloading stations) and user interfacing means distributed control and integration.
Many people try to get around these requirements by stating that the ‘Robot controller can do all of that’. Well, that may well be true, but remember it is a ‘Robot Controller’, not a ‘Machine Controller’.
|Robot controllers are great at controlling robots, but all these other tasks are typically harder to program and maintain inside of a Robot Controller, much like using a baseball bat to play hockey (you can almost do it, but not really). However, there are products on the market designed for Machine Automation Control, and the proper tool, properly applied, will always yield better results.|
|When planning a budget for an integrated robot cell, no matter how small or large, there are some good rules of thumb to use. If the robot cost is around $20K to $30K, then plan on the remaining control costing at least 50% to 75% of that overall number. If you figure in integration of the components into a control enclosure, then drafting and fabricating cost will cost as much again. So, a typical SCARA robot with safety and integrated machine controller in an industrial enclosure would end up costing anywhere from $40K to $50K or higher depending on size of the robot cell and process requirements.|
| The other “hidden” cost is the programming for the robot and the controls for startup, tool homing, operation, and system alarm and recovery. The main robot tasks are typically setup in just a short amount of time (8 to 16 hours) but a truly robust system recovery and homing sequence can take twice as long (or more) to develop and debug. That is a lot of time to spend on recovery methods but consider the cost of a robot crash and the damage that can happen to tooling, product, and the robot that will result in long downtime. This upfront engineering is well worth the time and effort for a smooth running, maintenance free machine.
Typically, I plan on 40 hours (at a minimum) for robot programming and testing and an additional 40 hours for programming the rest of the system for a basic robot application. If all the hours and the materials are added up, for a fully functioning robot cell with proper safety and controls a good initial budget would be somewhere in the $60K to $75K range for a fully integrated, basic robot control system.
| Keep in mind these costs don’t necessarily cover the mechanical design which is just as important to a robot cell as the controls. Mechanical considerations (and the hockey analogies thereof) will be covered in a future blog post.
All projects and activities have hidden cost, Robots and Hockey are no exception. If you take to the ice to play hockey but didn’t purchase a helmet, then it will not be an enjoyable experience. When doing preliminary budgeting for robot cells be sure to consider and include all aspects of the controls solution so the project runs smooth and gets into production as soon as possible, ideally without requiring the use of a helmet.