Servo - November 2015

78 SERVO 11.2015

images and digital range figures on a screen in the instruments.

Hackers used microcontrollers in the past to read the digital information from these handheld range finders for robot distance measurements before ‘made for robots’ sensors became widely available. Today’s very inexpensive micro electro-mechanical systems (MEMS) have allowed robots, quadcopters, and many moving platforms to sense orientation and motions, and be easily controlled. The latest MEMS technology has allowed complex navigation and appendage motions to be under total control of a microprocessor. Shaft encoders, accelerometers, gyros, and magnetic compasses have plummeted in cost from many hundreds of dollars to just a few bucks. The Pololu AltIMU- 10 shown in Figure 7 combines a gyro, accelerometer, and a compass IMU with an altimeter on a single tiny board. These MEMS chips have allowed robots to possess some amazing mobility and mobile apabilities. We have also made amazing strides in other robot sensor technology in the last few years. Budget-minded robot builders have access to long-range laser range finders such as the Light Ware SF- 10 series shown in Figure 8 from There are also now ‘intelligent’ video cameras designed for robots such as the CMUcam series costing from $139 to $259; the CMUcam3 module is shown in Figure 9. These cameras have proven very functional and quite useful for mobile robots.

What are the Main Stumbling Blocks in Robot Design?

I have been writing about all the amazing (yet inexpensive) sensors available to today’s robot designers.

We can talk to our robots and they can talk back, as well as see and follow us and obey our commands. Batteries can become a major problem when building human-sized bipedal robots, but not as much for smaller rolling mobile platforms. Software such as ROS, Python, C++, Java, Microsoft RDS, PBasic, Linux, and many other systems are available for builders using a Propeller, Arduino, Raspberry Pi, Beagle Bone, or any other type of microcontroller. So, what’s the problem here?

Let’s look back at those early computers again. They exploded in popularity when the CPU board was placed in the same ‘box’ as a floppy drive, and affordable and useful software was available on a floppy disc. The computer’s power supply was also an integral part, and the monitor could sit on top or be contained in the same case. Later versions added a hard drive, and we now had a computer that did everything we could imagine. We could play games, develop spreadsheets, and perform word processing with the addition of a cheap printer instead of using typewriters (on which the words could not be changed without an eraser or white-out). Home users and businesses gobbled them up by the millions as processor power increased, as well as the capabilities of various types of software.

Think about the earliest robots. The first personal and experimental robots started out small and grew larger. Boxes with little more than wheels were considered robots. Then, model aircraft servos were modified for continuous rotation for small one pound robots such as the Parallax Activity Bot and other similar experimental and educational robots. The larger commercial home robots shown back in Figure 1 that were destined to change the world (but did not live up to their hoped-for popularity) like the Hero 1 and 2000, RB5X, Topo, and the others, were cute but could really do little else. The Hero series and RB5X had arms, but they were quite inefficient and sufficient only for experimentation.