PRELIMINARY
Task Mobile Robot
This document provides a brief description of the Task mobile robot which incorporates an unusual variety of new ideas about robot design and construction. A list of basic design concepts and detailed specifications are described.
Basic Design Concepts
Modularity, Expandability & Standardization
Task will be hyper-modular to allow subsystems to be improved with minimal effort. New subsystems can be added easily as they become available without abandoning basic design concepts. Modularity will penetrate every aspect of the hardware, software and mechanics resulting in standardization of items such as connectors, circuit board sizes, bolt patterns and command structures. A secondary benefit of modulaity will be ease of repair. Even though this modularity will not be without cost, the payoff will occur throughout the life of the robot in reduced down-time and ease of enhancement.
Common Technology
A special effort will be made to resist the urge to use exotic technology that doesn't meet a realistic price/performance ratio. Components that are difficult to get or are at risk of being discontinued will also be avoided. Virtually all parts will have multi-vendor sources.
Distributed Control
Task subsystems will communicate to each other via a high-speed, multi-master serial network. Each subsystem has access to information from other subsystems. Subsystems can give and take commands from each other if needed. Programs and parameters within each subsystem controller can be modified by other controllers to allow for adaptation to different applications and environment. This gives the programmer complete freedom from hard-coded algorithms that require complicated work-arounds and will ultimately result in very sophisticated abilities. A central control computer and software will exist with various layers of controllers underneath, but centralized control of every function, while possible, will not be necessary. This arrangement will allow functions to be placed in the most logical and efficient place within the network hierarchy and is expected to result in greatly improved response time and performance.
Open Architecture
The Task architecture will be open to allow easy modification, enhancement and addition. Formal
specifications of the controller network, software functions and mechanical systems will be published to encourage and ease this process.
Universal Capabilities
As the name "Task" suggest, the abilities will accommodate the needs of many applications and tasks. Because applications are so varied, universal accessory plates will be made available all over the Task frame. This will allow multiple vendors to supply universal accessories without having to design one for each robot. Accessories could include arms, vacuums, grass trimmers, soil sample retrievers or special sensing equipment.
Specifications
Frame
* Extruded aluminum frame elements.
* Motorized torso rotates 180 degrees to allow for positioning of accessories such as an arm.
* Universal accessory plates on all sides and bottom with standardized power and controller connections.
* Vibration isolation components.
* Alt/Az mechanism on top of frame allows for positioning of cameras, range finders and other sensors.
* All subsystems easily removable using standardized fasteners.
* Removable, vacuum formed cover panels made from ABS plastic.
* Cavities and containers for payloads.
* Weight: 150 lbs., Size: 28" wide, 36" long, 48" high
Propulsion
* Front, dual DC drive motors with optical encoder feedback.
* Rear, dual-wheel idler.
* Over-current and other failure conditions detected.
* Adjustable gear ratio for terrain adaption.
* Optional 2-speed transmission.
Subsystem Controllers
Each subsystem is controlled by an intelligent controller. Each controller has a high-speed
microcontroller, memory and network communications hardware. Specialized circuitry is then attached to each controller board to allow it to provide the functionality necessary for the particular subsystem. Controllers can be programmed using any common PC-based language such as C, BASIC or Pascal, then downloaded to the controller.
Central Controller
A central controller is provided by a full-size 486 computer using a standard ISA bus. Any standard operating system can be chosen depending on application or simply preference. All standard PC hardware is available such as speech and video processing cards, communication boards and others. Any programming environment can be used for development.
* 486 PC with standard ISA Bus
* Keyboard and LCD.
* Network communications card.
* Sound processing card for speech recog & synth.
* Video capture card.
* 540 meg hard disk.
* 3.5" floppy disk.
* CD ROM Drive.
* Radio Modem.
Sensors
* Multiple ultrasonic range finding systems allow detection of nearby objects.
* Multiple optical range finders for more precise object detection.
* Touch sensitive panels on the frame for collision detection.
* Precision electronic compass.
* Precision, 2-axis tilt detector.
* CCD Camera.
* Light and sound level detectors.
* Temperature sensors.
* Optional GPS receiver.
Arm
* 4-axis. (plus torso=5)
* 2 lb. payload.
* 3-finger gripper with pressure sensors.
* 24" range.
* DC motor drive with optical encoder feedback.
Power System
The power system is a modular, intelligent subsystem that controls every aspect of power management. A series of batteries can be switched in and out to allow for charging and operation simultaneously. Battery status is tracked and information is made available to the rest of the system for decision making.
* Multiple 12 volt, sealed gel-cel type batteries.
* Easily removed or exchanged if needed.
* Intelligent power controller can select batteries, track charging, sense current draw, etc.
* Charging probe can seek charger connector at docking station.
* Solar panel cells for charging.
* Two sleep modes for power conservation.
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