ChrisAndGeorgeToTheRescueLab1-TheCricketBot

For the Cricket Lab my partner, George Murphy, and I decided to attempt the Search and Rescue Mission which we have titled: “Chris and George to the Rescue.” As the title indicates, George and I planned on programming a robot to navigate a building, while staying on the right hand wall, to find the stranded person (being represented by a blinking light). The idea behind this focuses on the white walls of the “building;” by having the robot respond to changes when the sensor identifies the black tape. However, we needed the robot to turn properly and identify the blinking light, which came down to analyzing data from the various sensors and simple guess and test, to discover how powerful the motors should be, how long they should run, etc.

Our first plan was uncomplicated; we simply needed to ensure that the robot would move forward in a straight line and then turn correctly, while getting close to and stopping at the blinking light. This was accomplished by first testing both the actuators, the DC motors, and the effectors, the wheels. Once finished, we decided to use three sensors: two light sensors, which would be placed on either side of the robot, and a touch sensor that would be placed in front. The idea of two light sensors was proposed so that when either one deviated from white light, that motor corresponding motor would shut off for a specified amount of time, allowing the cricket to turn at a broad curvature (some fraction of -x^2). Although there is probably a mathematical relationship between the powers of the motors, the gear reduction, torque, friction, and the general curvature to discover the time, we used simple guess and check to determine the necessary time for the turn.

However, we soon abandoned this plan once Mrs. Thomas told us that the Logo Blocks program could only sustain two sensors at a time. To accommodate this we decided to include the touch sensor and only one light sensor, to instruct the robot when to turn, by following the process in plan one: shutting off or reducing the power of one of the actuators. The touch sensor also plays an important role in the overall performance of the robot as it enables to robot remove itself from a corner, and is used to move as close to the blinking light as possible. When the touch sensor is pressed, as in the situation when the robot bumps into a wall, the actuators will reverse, in turn causing the effectors to reverse for a certain amount of time before instructing the robot to shut off one actuator, thus turning the robot. And when the light sensor detects the blinking light, by sensing the periodic brightening, it will move until it bumps into it before backing up, for a very short amount of time, leaving it close to the blinking light.

When programming the robot to properly navigate a building and stop at a blinking light, while remaining on the right hand wall, George and I ran into several problems. The first of them being that the wheels did not possess the same torque. This was fixed rather simply; by increasing the power of the actuator that controlled the wheel with the lower torque, we were able to ensure that the robot would move in a relatively straight line.

Once we had taken care of this first problem we moved on to programming the robot and while there were some complications, there was nothing serious at first. We managed to ensure that the robot would turn when there was a change in light however the “building” was in a dark corner of the room and we needed to take this into account. By attaching a LED Number Display to the cricket we were able to discover the reading taken by the light sensor in the shadowed corner of the room and reprogram the robot accordingly. However, other problems soon arose and as we added a function to the robot to include the touch sensor we could not figure out how to program this second function in, as we had created a loop to ensure that the robot would use the light sensor to check for changes in the brightness around it. Once we had asked Mrs. Thomas, who explained how to fix the problem, we did so and are now just tweaking it, as the actuators reverse when the robot is first turned on because the touch sensor function has been set to occur first.

In conclusion, George and I have managed to program a Cricket Robot and are now just fixing several minor problems to ensure our success in The Search and Rescue Mission.