Michael A. Tyborski
Robots are rapidly becoming part of our life. You cannot read a magazine or newspaper without hearing about them. Although robots were once laboratory curiosities, they are now within anyone's reach.
Yes, you can own a robot. Mechanical servant? Not yet. Entertaining companion, yes.
Androbot, Inc., of Sunnyvale, California, has recently released its Topo robot. It will provide hours of entertainment for any Apple owner. Although not a true robot, it demonstrates many of the important fundamentals of robotics.
Your Computer Controls It
Topo is a radio-controlled platform that looks like a robot. It includes a user's manual, transmitter, and plug-in control card for the computer. It also includes TopoBASIC on disk, which allows it to be used within a few minutes.
An Apple computer controls Topo; this simplifies programming and reduces the selling price. It also eliminates the need to learn a new operating system or programming language. Unfortunately, your computer does not receive sensor information, a limitation that makes it possible for Topo to run into walls or down the stairs.
The robot is made of high-impact plastic and is three feet tall. Its friendly appearance attracts small children like ice cream, an effect consistent with Androbot's belief that robots should be "friendly looking, inviting companions."
Topo has a head and arms. Unfortunately, they are not functional. The head is permanently attached to the body and does not turn, which makes the robot less lifelike. It has a decorative face grill and eyes. An emergency stop switch is mounted on top of the head which turns off the robot.
The arms, plastic flaps that can be extended as needed, are made from relatively thin plastic and cannot hold heavy loads. They attach to the body with plastic pins.
Two-Wheel Drive System
Topo has a unique drive system called Andromotion. Androbot claims that this provides "maximum stability and safety with optimum maneuverability and control." It also gives the robot an individual personality.
Just what is Andromotion? It is a two-wheel drive system that relies on angled wheels for stability. This design is patterned after the rocking chair. As a result, the robot remains stable because the effective roll center is above the center of gravity. The principle is clearer when the robot is viewed from the side. The side projection of the wheels looks like an ellipse, and the long sides resemble the rail of a rocking chair.
Because of Andromotion, Topo sways from front to back as it moves. This sway can become violent during a fast stop, making Topo look like a fishing bobber.
Androbot's Topo robot.
Androbot states that Topo has industrial-grade batteries and a fabricated steel superstructure, and claims that high-torque motors and cast aluminum gear boxes assure structural integrity. These features place the robot above the toy category.
The robot's back panel holds the power switches, indicator lights, and a charger jack. Yes, switches. For some reason, Androbot decided to use a separate ON and OFF switch, a design possibly based on a control circuit restriction. The red and green switches may also indicate STOP and GO to children.
The indicator lights show when Topo is on and what the battery status is. When a low voltage condition occurs, a red indicator light turns on. The wheel supports also contain indicator lights for showing direction.
You are responsible for plugging in the charger – a simple AC adapter. You must also prevent the robot from being turned on while charging. If it is, you may soon need a new charger. Finally, you must not leave the charger connected for more than 24 hours at a time.
Topo receives commands over a radio link. This link uses a 100-milliwatt, 4-channel AM transmitter that operates at 27.145 megahertz, and transmits the control card data. Although the antenna is short, a 90-foot range is possible. The transmitter has its own power switch to prevent interference when Topo is not being used.
The control card provides power and serial data for the transmitter. It plugs into slot five on the Apple computer. The unit has three integrated circuits and one regulator. This allows a 3-inch-square board to hold all the circuitry. An AMD 9513 chip generates the serial data for the transmitter.
The Topo manual is easy to read and understand. It comes in a small ring binder and includes dividers for future chapters. A plastic holder protects the program disk and warranty card. Interestingly, the manual was printed on a dot matrix printer, but this does not decrease its readability.
After an introduction to Androbot and Androbots, the user is shown how to unpack and check Topo. The first section also includes control card installation and battery charging instructions.
The important calibration procedure, which insures accurate movement and turning, is covered next. Finding calibration values for each surface Topo will move on will minimize errors from wheel slippage.
Finally, the last section describes TopoBASIC, and has material for the beginning and advanced programmer. This section includes a listing of the machine language and BASIC routines. It also provides a glossary of BASIC routines.
Topo In Motion
After charging the batteries, we began to use Topo under program control. This proved to be an interesting experience. Topo just did not like repeating its path. While drawing a square, for example, it turned about 15 degrees each repetition. This made the square rotate about its center.
Proper calibration improved its performance. In our case, the procedure took about ten minutes. It had to be repeated, however, for other surfaces.
The transmitter could control Topo throughout a house. It did have some annoying dead spots, however, which made Topo act erratically or stop.
Topo cannot detect obstacles. As a result, it often ran into people or furniture. This, in turn, changed its path or completely stopped it. Whenever this happened, it had to be stopped and moved to its starting point. The program was then restarted.
Spectator reactions varied. Adults and teenagers were either amused or skeptical. Many wondered what Topo could be used for. Young children, naturally, were a captive audience. They would try touching Topo whenever it stopped. Some even talked to it.
Having already seen Heathkit's Hero robot, many people missed voice and head movement, claiming that these features make robots interesting and lifelike. A few people also wanted the arms to move. Despite these objections, they all gave Topo a favorable rating.
Androbot will offer a number of accessories for Topo, including a voice module and Androwagon.