Have you ever seen this video with a cat wearing a miniature shark costume and riding a robotic vacuum cleaner? For the cat lovers out there this video is every bit as awesome as it sounds. If you happen to be a dog lover, not to fear! If you check out the related videos sidebar you can see videos of dogs doing the same thing.
As a validation engineer, I can appreciate a video like this not only because pets are awesome, but also because it demonstrates the quality of the final product. This is especially true in one video where we see a full-grown Siberian husky riding the robotic vacuum.
You may be thinking, “What’s the big deal?” Well, huskies can grow to be more than 60 pounds, whereas the robot itself weighs only 8.4 pounds. With the dog’s additional weight, the load on the drive train is increased. To continue to move, the motor now requires more torque to compensate for the additional load. This translates to a higher current draw from the battery and additional stress to the electronics in the form of heat. In an improperly designed system, conditions such as these could result in anything from a blown fuse to system overheat and catastrophic device failure.
Yet, instead of device failure we see the robot continues to move and vacuum even under a load 800% greater than what it was originally designed for. That’s pretty impressive! I can tell the robot is robustly designed and was thoroughly validated before it was released to market.
Let’s pretend that wasn’t the case, though. Could you imagine how different things would be for that company if the vacuum caught fire when the dog sat on it? Instead of a viral video, they’d have a massive recall.
This is how the idea of validation was born. Validation refers to testing the functionality of a device or system in real-world and often extreme operating conditions. Products that are not thoroughly tested tend to get recalled, which hurts company image and profit and, even worse, sometimes people. In the Motor Drives group at Texas Instruments, we have a philosophy on recalls: we don’t want them to happen.
That’s where I come in. As a validation engineer, it’s my job to put our parts through the ringer. I act as the first customer of the device and treat it as though I am evaluating it for the first time. I look at the datasheet with no assumptions and test the part in real-world conditions to make sure it does exactly what we say it will do. If there is some weakness in the device, I report my findings to our design team, which they will use that data to make the device more robust.
We test all released devices in the Motor Drives portfolio over their entire operational voltage range, minimum and maximum currents, and a wide range of temperatures. I check the protection circuitry (such as over-current protection and thermal shutdown) and make sure that these systems correctly protect our devices under harsh operating conditions. I also test the functional operation of the device over this range of conditions to ensure that, if a customer does something unexpected, the device still meets specified performance requirements.
I engineer some of the tests I perform to cause catastrophic damage to the device, because by doing so we learn about its limits. Like the show “MythBusters,” I get to blow things up for science! Plus, they give me some pretty neat equipment to use. Check out my validation bench below. I call it The Gauntlet.
Figure 1: Motor Drives validation – The Gauntlet. Fallen soldiers of the most recent validation effort are circled in red.
With engineers like me all across TI running similar tests on their devices, you can be assured that our parts will perform as specified.
Additional resources:
- For design questions, visit the TI Motor Drivers forums on the TI E2E™ Community.
- For reference designs, visit the Motor Drives section on the TI Applications page.
- Learn more about the DRV8701, a new single H-bridge gate driver.