Task - Calibrate a single sensor with the Advanced Light/Color technique
As an exercise try to implement the calibration of the minimum and maximum values for a single sensor.
- #639
- 04 Oct 2017
As an exercise try to implement the calibration of the minimum and maximum values for a single sensor.
Implement the program for array initialization.
Follow the video tutorials for initializing arrays and implement the program.
Many times we just upload blocks and leave it up to you to use it. In this tutorial, I would like to show you how to use the implemented blocks. How to import them into the EV3-G software. How to see them in the palette. How to drag and drop them to build a working program.
Following the Advance Sensor Calibration course section, we found the min and max values detected by each sensor. Now it is time for the real deal of the calibration. Detect the current value from the sensor and find what is the percentage of this value for the range between min and max.
In the course section for Advance Sensor Calibration we previously showed you how to find the minimum and maximum value for a single LEGO Mindstorms Color Sensor and to store this value in an array. The program was implemented with the EV3-G software. In this tutorial we are going to find the Min and Max for all the four sensors and to store all the 8 values in an array.
In this tutorial, we would implement a program that finds the minimum and maximum value detected by the sensor and stores this two values in an array.
"Array initialization" is the first step in every program that involves Arrays. This applies to most programming languages and for EV3-G it is a must.
In this tutorial, we would show you how to initialize the array and how to extract this logic in a new block
Building a rack is a very important skill during competitions. You should try to build one, learn how to use it and have it as a tool for you next robots. But for this particular BoxRobot, we will not continue with a rack.
Using the rack depends on the experience of the team. Based on this a different number of gear wheels and racks would be used.
The next step of lifting a robot to a mission model is to try to use a rack.
Think of an attachment that leaves the Gecko on the mission model. Don't use the robot attachment that we already have. Just the box robot and the gecko. Nothing should support the Gecko when it is hanged on the mission model.
In this tutorial, we add another mission to our current program. This mission is - hanging the Gecko from the FIRST LEGO League Animal Allies.
What should you as a teacher know when the students are trying to achieve a program and robot attachment that could reproduce their behaviour 9 out of 10 times.
The task in this tutorial is to execute the program 10 times and to do it yourself. If you have your attachment then use it. If you have our attachment then use it. But execute the program 10 times and make sure that it works.
How great is the great attachment for lifting that we built in this course? How many times can it lift the robot without making an error? How great are your attachments and how could you test them? - the answer is simple. Just try 10 times and they should work at least 9 of them as our attachment is.
If you've done the calculation following the previous tutorials you would arrive at a result of 18.75 rotations. But this is not the correct answer. The calculation is wrong, because the math model that we've built, although kind of obvious, is not correct. When experimenting the correct number of rotations would be 37.5. This is a large difference. Two times larger. Exactly two times large. Something should be happening here - and this thing is "planetary mechanism"
This is a teacher's note about the math behind calculating gear ratios with for our lifting attachment. It math model we build in previous tutorials is not exactly correct and here is the explanation why.
Sometimes the answer that you get by calculating seems not to be right. Is it the calculation that is wrong. Probably it is not the calculation, but something is happening with the robot.
In the previous video, we found the correct answer for our task and it is 18.75, or is it?
What should you do as a teacher when the students are calculating the gear ratios and number of needed rotations?
We calculate the number of rotatios when a gear system is involved. The driving wheel will have to do a number of rotations for the driven wheel to rotate to a desired number of degrees. In our specific case when the driven gear wheel is rotate to about 90 degrees the legs will lift the robot.
Let us do a quick recap of the whole lifting mission and its solution
Note for the teacher on making the construction more stable, more durable and using beams for this.
Following the principles from the previous video, try to make the attachment that you've built, more stable and durable.
In this video we discuss the durability of the construction of LEGO robots and how do we make them more durable.