Tham khảo tài liệu 'mcgraw-hill - the robot builder's bonanza part 8', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CALCULATING THE SPEED OF ROBOT TRAVEL 231 FIGURE In tricycle steering one drive motor powers the robot a single wheel in front steers the robot. Be wary of short wheelbases as this can introduce tipping when the robot turns. motor of course . Read more about servo motors in Chapter 20 Working with Servo Motors. OMNIDIRECTIONAL To have the highest tech of all robots you may want omnidirectional drive. It uses steerable drive wheels usually at least three as shown in Fig. . The wheels are operated by two motors one for locomotion and one for steering. In the usual arrangement the drive steering wheels are ganged together using gears rollers chains or pulleys. Omnidirectional robots exhibit excellent maneuverability and steering accuracy but they are technically more difficult to construct. Calculating the Speed of Robot Travel The speed of the drive motors is one of two elements that determines the travel speed of your robot. The other is the diameter of the wheels. For most applications the speed of the drive motors should be under 130 rpm under load . With wheels of average size the resultant travel speed will be approximately four feet per second. That s actually pretty fast. A better travel speed is one to two feet per second approximately 65 rpm which requires smaller diameter wheels a slower motor or both. How do you calculate the travel speed of your robot Follow these steps 1. Divide the rpm speed of the motor by 60. The result is the revolutions of the motor per second rps . A 100-rpm motor runs at rps. 2. Multiply the diameter of the drive wheel by pi or approximately . This yields the circumference of the wheel. A 7-inch wheel has a circumference of about inches. 3. Multiply the speed of the motor in rps by the circumference of the wheel. The result is the number of linear inches covered by the wheel in one second. With a 100-rpm motor and 7-inch wheel the robot will travel at a top speed of inches per second or just under
