Pay attention to peak current which transistor can handle. Also pay attention to Vce-sat, the voltage across the transistor when it is switched on. Vce-sat times the collector current is the power which the transistor must dissipate. Too much and the device will first smoke then melt.
In the toy car that Etienne-Cummings adapted, two sensors are mounted as &quot;eyes&quot; on the front of the vehicle. The microchips force the car to follow a line detected by the sensors, unless an obstacle appears in its path. To the chips, avoiding a crash takes priority over following the line, so they steer the car away from the obstacle. The system also &quot;remembers&quot; how it turned to avoid the obstacle so that it can steer the car back to the line to resume its original course. Etienne-Cummings has also begun working with Johns Hopkins biomedical engineering researchers who are creating computer models of the heart. He hopes to use computational sensor technology to enable a robot arm to keep pace with a beating heart. If this technology is perfected, surgeons of the future may be able to use the robot to clear a blocked cardiac artery without having to stop the heart first, as doctors must do today. Tiny custom microchips like these give &quot;vision&quot; to a toy car by processing images and telling the vehicle how to respond. Photo by Mike McGovern To achieve such advances, closer collaboration between microchip designers and the mechanical engineers who build robots is essential, Etienne-Cummings says. &quot;The people who assemble robots don't have access to the sensors that I design,&quot; he says. &quot;I think that's one of the things that has prevented computational sensors from making greater inroads in robotics. We are two divided communities, and we haven't been talking to each other. Now, we're finally starting to have those conversations.&quot; Etienne-Cummings, who was born in the islands of Seychelles off the coast of Africa, earned his doctorate in electrical engineering at the University of Pennsylvania. He joined the faculty of Johns Hopkins' Whiting School of Engineering in the summer of 1998. Color slides of Ralph Etienne-Cummings and his system available; contact Phil Sneiderman Related Web Sites Ralph Etienne-Cummings' Home Page Johns Hopkins Department of Electrical and Computer Engineering Johns Hopkins University news releases can be found on the World Wide Web at http://www. jhu . edu /news_info/news/ Information on automatic e-mail delivery of science and medical news releases is available at the same address. Go to [email_address] Home Page
About The Picture above: Sculpture created from a single steel plate, 30&quot; square, utilizing a Hilbert curve (level 5) as the tool path. One continuous cut, 77 feet long. (1994). The ability to precisely control the path of a tool enables fabrication of objects that would not be possible or practical by hand held methods. Despite their increasing use in industry over the past decades, the high cost of robotic tools has essentially prohibited their use by artists.
Au-ton-o-mous adj. Not controlled by others or by outside forces; independent: an autonomous judiciary; an autonomous division of a corporate conglomerate. Independent in mind or judgment; self-directed. Independent of the laws of another state or government; self-governing. Of or relating to a self-governing entity: an autonomous legislature. Self-governing with respect to local or internal affairs: an autonomous region of a country. Autonomic. [From Greek autonomos: auto-, auto- + nomos, law; see nem- in Indo-European Roots.]
Robotics Sensors & Controllers Sensors collect all the information a robot needs to operate and interact with its environment. What are sensors? What are Controllers? Controllers interpret all the input from the sensors and decide how to act in response.
Robotics Sensors & Controllers What are sensors for? The control of a manipulator or industrial robot is based on the correct interpretation of sensory information. This information can be obtained either internally to the robot (for example, joint positions and motor torque) or externally using a wide range of sensors.
Robotics Sensors & Controllers <ul><li>Since sensors are any device that provide input of data to the robot controller a wide verity of sensors exist. Some basic types of sensors are shown including: </li></ul><ul><li>Light sensors which measure light intensity. </li></ul><ul><li>Heat Sensors which measure temperature. </li></ul><ul><li>Touch sensors which tell the robot when it bumps into something. </li></ul><ul><li>Ultra Sonic Rangers which tell the robot how far away objects are. </li></ul><ul><li>And gyroscopes which tell the robot which direction is up. </li></ul>Types of Sensors
Robotics Sensors & controllers The bumper skirt on this robot is an example of a touch sensor. When the robot runs into a wall the bumper skirt hits a micro switch which lets the robot controller know that the robot is up against a wall. Other types of touch sensors are used internally to let the robot know when an arm is extended to far and it should be retracted or when the robots other physical limits are reached.
<ul><li>Light sensors are used to detect the presence and Intensity of light. These can be used to make a light seeking robot and are often used to simulate insect intelligence in robots. </li></ul>Robotics Sensors & controllers
<ul><li>Heat sensors help robots determine if they are in danger of overheating. These sensors are often used internally to make sure that the robot’s electronics do not breakdown. </li></ul>Robotics Sensors & controllers
<ul><li>Ultra Sonic Rangers are used to determine how far a robot is away from an object. They are often used by robots that need to navigate complicated terrain and cannot risk bumping into anything. </li></ul>Robotics Sensors & controllers
<ul><li>Gyroscopes are used in robots that need to maintain balance or are not inherently stable. Gyroscopes are often coupled with powerful robot controllers that have the processing power necessary calculate thousands of physical simulations per second. </li></ul>Robotics Sensors & controllers
<ul><ul><li>Use transistors as a switch to control power to motors, relays and lamps. Current and power handling capability is pretty much dictated by package size. The bigger the package, the more power. </li></ul></ul>Robotics Sensors & controllers <ul><ul><li>Transistors </li></ul></ul>
<ul><li>Basic Stamp II The Basic Stamp II is a small, self-contained computer controller manufactured by Parallax Inc. This easy-to-use system is programmed using a Basic-like language called PBasic. Programs are written on an IBM-style PC then downloaded to the Basic Stamp II for execution. Large libraries of programs can be created and saved. </li></ul>Robotics Sensors & controllers Controllers
<ul><li>Tiny custom microchips like these give "vision" to a toy car by processing images and telling the vehicle how to respond. </li></ul>Robotics Sensors & controllers Controls
<ul><li>Motion control is the process of computer controlled kinetics-- the foundation of robotics. CNC (computer numeric control) is an antiquated term for this process, recalling an era when programmers entered the numeric commands and coordinates for each machine move. </li></ul>Robotics Sensors & controllers Motion Control
Robotics Glossary <ul><li>Au-ton-o-mous adj. </li></ul><ul><ul><ul><li>Not controlled by others or by outside forces; independent: an autonomous judiciary; an autonomous division of a corporate conglomerate. </li></ul></ul></ul><ul><ul><ul><li>Independent in mind or judgment; self-directed. </li></ul></ul></ul><ul><ul><ul><ul><li>Independent of the laws of another state or government; self-governing. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Of or relating to a self-governing entity: an autonomous legislature. </li></ul></ul></ul></ul><ul><ul><ul><ul><li>Self-governing with respect to local or internal affairs: an autonomous region of a country. </li></ul></ul></ul></ul><ul><li>Click here to return to Slide 10 </li></ul>
<ul><li>android An"droid ([a^]n"droid), </li></ul><ul><li>A machine or automaton in the form of a human being. </li></ul><ul><ul><li>Possessing human features. n. </li></ul></ul><ul><ul><li>An automaton that is created from biological materials and resembles a human being. Also called humanoid. </li></ul></ul>Robotics Glossary <ul><li>Click here to return to Slide 4 </li></ul>