Need help coming up with an equation for a bend angle calculation

Click For Summary

Discussion Overview

The discussion revolves around finding an equation to calculate the bend angle of a tube based on distance measurements from a laser. The context includes practical application and mathematical reasoning, with a focus on achieving high resolution in angle measurement.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Homework-related

Main Points Raised

  • One participant describes the need to convert distance measurements to an angle for a tube bend, specifying a range from 92 degrees to 88 degrees with a nominal of 90 degrees.
  • Another participant requests clarification on the distances involved, specifically the horizontal and vertical distances from the laser to the tube.
  • A participant provides the vertical and horizontal distances, correcting an earlier misstatement about the distance from the laser to the tube.
  • A proposed formula for calculating the angle is given as angle=atan2d((100-x), 311) + 90, with the condition that the angle is less than 90 when the distance exceeds 100 mm.
  • One participant seeks clarification on how to use the atan2d function in an online calculator.
  • A later post indicates that the participant has understood the proposed solution.
  • Another participant inquires about alternative ways to express the atan2d function, noting that their controller supports atan and atan2 instructions.
  • It is mentioned that atan2d differs from atan2 in that the former outputs degrees while the latter outputs radians.

Areas of Agreement / Disagreement

The discussion includes multiple viewpoints regarding the mathematical approach to calculating the bend angle, with no consensus reached on the best method for implementation in the specific controller mentioned.

Contextual Notes

Participants express uncertainty about the best mathematical functions to use given the limitations of their equipment, and there are unresolved questions about the applicability of the proposed formula under different conditions.

nddwind
Messages
5
Reaction score
0
Apologies if this is the wrong forum.

I have an application where I need to measure the bend angle of a tube and display the resulting angle on a screen. I am using a laser mounted in a fixed location which reports distance back to my controller, (scaled to millimeters.) I am measuring from 92 degrees to 88degrees with 90 degrees being nominal. Is there a formula for converting a distance measurement to an angle? I am aiming to achieve .05degree resolution, so 90.05degrees, 90.1, 90.15, etc.. At first I thought that because the distance and range that I was measuring was so short I could use a simple linear equation to scale my distance to an angle but it seems that the rate of change between each degree is much higher than I thought. Also if it helps I'm about 18 inches away from the bend radius.

I am pretty terrible at math, and I'm not even sure if this would be described as a differential equation that I am looking for.

I've attached a picture if it helps.

Thank you for your time.
 

Attachments

  • Laser_Measurement.gif
    Laser_Measurement.gif
    5.1 KB · Views: 191
Mathematics news on Phys.org
More information is needed. Is 18 inches the horizontal distance from the laser to the tube at ##90\deg##? What is the vertical distance from the tube pivot point to the laser intersection point?
 
Vertical distance from pivot point to the point on the tube that the laser hits is roughly 311mm, horizontal distance is 100mm from tube at 90 degrees. (the 18inches I provided was way off)

Thank you
 
Try angle=atan2d((100-x), 311) + 90, where x=distance from laser to tube in mm and the angle is less than 90 when the distance is greater than 100.
 
Thank you for the reply, how would I use atan2d, or how could I enter that equation into a online calculator like desmos
 
Think I got it, thank you
 
Is there another way to write the atan2d function? Or write the equation you gave without using the atan2d function? My controller doesn't have that math option

Thanks for all the help

My controller does has atan and atan2 instructions
 
Last edited:
I believe the only difference between atan2 and atan2d is the first is in radians and the second is in degrees
 

Similar threads

High School I don't understand how this equation calculates angle for hexagons
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Dimension of an Angle: Clarifying the SI Standard
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad Help creating a coordinate system for a robotic arm
  • · Replies 5 ·
Replies
5
Views
3K
Refraction through different mediums: calculating multiple angles help
  • · Replies 6 ·
Replies
6
Views
2K
Finding coincident angle between 2 equally spaced sets
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Simple math model for a Particle Image Velocimetry system
  • · Replies 6 ·
Replies
6
Views
1K
Looking for equation/formula for calculating boomerang trajectory based on few variables for game
  • · Replies 1 ·
Replies
1
Views
3K
Undergrad Trying to reproduce curves with angle of CMB anisotropies
  • · Replies 1 ·
Replies
1
Views
2K
Why Do We Not Calculate Angle Change in Plastic Container?
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad Non-Constant Angular Acceleration
  • · Replies 6 ·
Replies
6
Views
3K