Building a Pinball Model in LabVIEW

Modeling and simulating physical objects is a very popular scientific research method. Generally speaking, this application can be implemented using C language or Matlab . As a programming language, LabVIEW can also easily build models, especially the Simulation Module of 8.2 , which makes simulation modeling more convenient and intuitive. This article will take the implementation of a bouncing ball model as an example to introduce three ways to use LabVIEW to build models.

1. Simulation Module

The Simulation Module is relatively new to LabVIEW , but I believe it will have more powerful functions in future versions and will be more complete and easy to use. The program for modeling an elastic ball using this module is as follows:

As you can see, the entire model has three adjustable parameters: elastic coefficient (the ratio of the ball's velocity to its original velocity when it hits the ground), initial velocity, and initial height. In the Simulation Loop , the gravitational acceleration g is first integrated to obtain the velocity value, and then integrated to obtain the position value. It also determines whether the position has passed the 0 point (i.e., whether it has hit the ground). If it has passed the 0 point, the velocity is multiplied by the elastic coefficient and the position is reset to 0 .

2. G Code

Without the Simulation Module , this simple physical model can be simulated using only LabVIEW G code. The following figure is a program written in LabVIEW :

As can be seen from the figure, we use the For loop to make the simulation loop count 200 times , and the dt of each time is 0.1 . According to dt and the physical dynamics formula, we can get the current speed and position information, and then perform the zero detection as in the previous example, and perform the corresponding operation. It can be seen that programming with LabVIEW is a little cumbersome, mainly because there are too many mathematical operations, which makes the entire Diagram occupy too much space.

3. Mathscript

Mathscript is also a new feature of LabVIEW 8.2 . Currently, LabVIEW advocates a mixed programming method of text and graphics, which can take into account the advantages of both programming methods and maximize development efficiency. The following figure is a simulation code written in Mathscript :

The entire Mathcript code is m - code, that is, as long as you can run these codes smoothly under Matlab , 90% of them can be directly pasted into this node to run. If you study the program carefully, you can see that its operation method is similar to that of G Code , but because of the use of text programming, the code is more efficient, which is also the biggest reason why hybrid programming is used.

The following is a comparison of the results of these three simulation methods: