As can be seen from the video, Ultrabot chomps his jaws and chases Alex when he gets very close, but stops when Alex leaves the vicinity.
Our robot, Ultrabot, has been assigned the task of being our personal guard dog. He is instructed to scare off anyone that dares to come close to our treasure chest, frightening them with his vicious jaws as well as chasing them until they leave. Once nobody is within range, he returns to being his own happy dogbot self.
About our robot - "Ultrabot"
||Video of Ultrabot's successful defence||
About the Motion Sensor
The Motion Sensor, also referred to as the Ultrasonic Sensor, is one of two sensors that provide "vision" for the robot (the other being the Light Sensor). It is very helpful to enable to robot to see and recognise objects, avoid obstacles, measure distance and detect motion. The Motion Sensor uses ultrasonic technology, which is used in submarine sonars and used naturally by bats to detect motion. The ultrasonic technology measures distance by projecting a sound wave (like an echo) in a 30º arc and calculating the time it takes for it to encounter an object and return. Please refer to the video below to see the technology applied on the Motion Sensor. Large-sized objects with hard surfaces return the best readings, while objects made out of soft fabric or curved (like a ball) or are very thing/small may be difficult for the sensor to detect. Also, please note that two or more motion sensors operating in the same room may interfere with each other's readings. The NXT Motion Sensor is capable of measuring distances from 0 to 2.54 metres with a precision of +/- 3 centimetres. It returns a byte value expressed in cm, where 0 to 254 represents the object's distance in centimetres, and a reading of 255 indicates that there is no object within measuring range.
In the industry, ultrasonic technology can be very useful in monitoring levels of products, especially in the manufacturing and processing of goods. Ultrasonic sensors can accurately measure the level of liquid in a tank by calculating the distance from the sensor (top of the tank) to the bottom of the tank, and subtracting from it the distance from the top of the tank to the water level. This technology not only assists in monitoring liquid levels in which the information can then be applied in processing, but can also manage and prevent critical issues of the liquid overfilling.
This robot created by "Digsys II HIOA" is an amazing project that demonstrates what can be accomplished with four servo motors, two linear actuators, two ultrasonic sensors, two touch sensors and two colour sensors. The ultrasonic motion sensor is used to detect the gap in which a bridge shall be placed above. They are situated to face down onto the ground at the front of the robot, so once the lack of an object (ground) near the sensor is detected, the robot can move back and be ready to place the bridge. Without the ultrasonic sensor, the robot would not be able to know that it is approaching a gap, and will fall down it.
Industrial application of a motion sensor:
A Lego Mindstorm project that uses the motion sensor:
Investigation
Ultrabot, powered by the NXT Brick, is instructed to move his jaws and chase his target to scare them off when they are within a certain range (60cm). The NXT Motion Sensor detects targets that are within a certain distance from him, which activates a sequence that moves his electronic jaws and chases the target. He is also instructed to stop his scary program and return to his happy dog self when no targets are in the vicinity anymore. This technology can also be used in alarms to alert intruders to stay away.
Note: Very slow robot. Make sure you watch in x2 speed! (Settings Cog --> Speed --> 2)
