gabemorris12 / mechanism Goto Github PK

It currently appears that the same Mechanism object cannot support both calculate() and iterate() operations simultaneously -- Mechanism.pos is assumed to be unchanging (or at least always of the same type). It would be helpful if the class object itself left the independent variables unspecified, so that the same object could be used to solve for multiple specific configurations, or looped to make an animation / result table, and so on back and forth.

example proposed use case:

• Define joints, links, loop function
• Create Mechanism object
• Calculate configuration for input = (0, 0)
• Animate configurations for input = (linspace(0,1,10), 0)
• Animate configurations for input = (0, linspace(0,2*pi,50))
• Calculate configuration for input = (0.5, pi/2)
• ... (etc)

(This may also help with some DRY -- the iterate code could call calculate() rather than doing its own math)

Hi,
I was wondering if it is currently possible to specify the joints' initial positions (preferably as cartesian coordinates) in a linkage prior to iterating/generating a path of motion?

For example, in the below code snippet:

from mechanism import *
import numpy as np
import matplotlib.pyplot as plt

# Declare the joints that make up the system.
O, A, B, C = get_joints('O A B C')

# Declare the vectors and keep in mind that angles are in radians and start from the positive x-axis.
a = Vector((O, A), r=5)
b = Vector((A, B), r=8)
c = Vector((O, C), r=8, theta=0, style='ground')
d = Vector((C, B), r=9)

Is it possible to specify initial joint positions that would then get used by the mechanism object?

Also, thank you for your great contribution! It's really modular and readable 👍

In example of four bar linkage, link e is integral with link c and sits at a fixed angle with respect to it. I cannot find anything in the code to govern such behaviour.

Is it possible in general to specify for link a link:

1. which link to be integral with?
2. at what angle with respect to such link to sit at?

Hello.
I have a variable lengh on a bar due to a linear actuator, the triangle vector has 3 points (A B C), where A and C are blocked, B its the unknown position. How do you configure the script?, thank you so much and congratulations for the contribution.