Share this page

A Toy System

Introduction

Building a system is at the core of the Simumatik platform.

A system can be defined as a set of interacting components.

Behaviours and attributes set the rules for the interactions. This includes physical, electrical and mechanical attributes.

By running a system in a simulation we get to view and analyse it as it would behave in the real world. A system grows from simple to complex, but the basic principles for building one stays the same. The toy system you are about to build in this module may seem a little trivial, but the concepts are fundamental to anything you build in Simumatik.

Learning Outcomes

In this module, you will learn the basics of building a system, building on what you learned in the previous module. When finished you should be able to create a basic, non trivial system by yourself. You will learn to use component ports and how to control component interactions. The knowledge you get from this module is one of the core foundations of working with the Simumatik Platform, and you will have a great opportunity to further develop your skills in further modules.

Prerequisites

You need to be familiar with the basic functionality of the workspace, and how to add and place components.

The academy module ‘Getting Started’ covers all the basic skills needed.

Concepts

Product – A product is a type of entity that is dynamically created while the simulation is running. It can be anything, but as the name suggests it’s conceptually some kind of product that is processed in the system.

Product Entry – Where the products are entering the simulation.

Product Exit – Where the products exit the simulation.

Keywords

System
Conveyor
Sensor
Product entry
Product exit
Modeling

Components used

Door
AC motor
motor contactor
photoelectric sensor, conveyor

Table of contents

Overview

The most basic system consists of simple objects that interact directly through their innate properties, such as physical interactions between objects. These systems may give valuable observations, but contain no logic and do not achieve anything.

The system you are about to build needs to solve a problem. It consists of a set of conveyors where a product is transported. The path is blocked by a door, and we need to model the system in a way for the door to open, so the product can exit the system.

To achieve this we use a photoelectric sensor that controls an electric motor. The motor then opens a door. We go from the physical world, where the sensor reacts to an object, to an analog electrical signal that drives the motor, and finally the mechanical door back in the physical world.

a) Building the system

For basic knowledge about how to use the platform interface please refer to the manual. The exact positioning of the components isn’t important as long as the functionality is preserved. Get an overview from the conceptual sketch above, and start laying out the components, starting with the conveyors. When you are done with the necessary components for this exercise, you can continue to add some purely visual components to give the system a more professional look. There are several components for this purpose included in the standard libraries.

b) Power sources

We need two types of power sources. A 24V DC power supply for the photoelectric sensor, and an industrial 3 phase socket. For aesthetic reasons these may preferably be placed in an electric box or similar component.

c) Conveyors

Connect two or three medium sized conveyors and attach AC motors to each of them. Remember that ports can only have one input, so the connection needs to be done from the side of the connected component. Connect the phases of the motor to the industrial socket.

d) Door

The door should physically block the conveyor. Place it at the end of one of the conveyors as depicted in the blueprint. Connect a motor to the door.

e) Product Entry & Exit

Add a product entry and a product exit to the system. Choose a suitable product that fits through the door. Ducks make perfect products in this setting. The default values are fine as a start, but take your time to try out some different values.

f) Sensor & Logic

Place the sensor in front of the door. You may have to try out different placements until you find one that is close enough to the door for the products to pass through. The sensor reacts when an element enters its view, represented by a yellow rod. It then activates and sends a 24V current through its signal port. It is powered by two ports, x1 and x2, that has to be connected to the DC power supply.

We use a motor contactor as an intermediary between the sensor and the motor. The contactor has five inputs and three outputs as shown here. The inputs are the three phases, I1_in … I3_in, and the ports x11 and x12 used to control the current flow.

The input is routed to the outputs , I1_out … I3_out, depending on the control current on the ports x11 and x12, where x11 is connected to the signal port on the sensor. When the signal activates, the motor contactor delivers power to the motor.

Breakdown of the steps in the model:

The product hits the sensor.
The sensors signal output sends 24V
The motor contactor reacts on the control signal and routes its input power to the output power.
The engine receives power via the motor contactor and opens the door.

g) Running the system

Products enter the system and travel via the conveyors. When a product hits the sensor, the door should open, letting the product through. The speed of the conveyor may need to be adjusted in order for the door to open fast enough to let the first product to pass. Alternatively you can adjust the distance between the sensor and the door.

Conclusion

You have now built your first system from start to finish. Compared to an industrial system it is very simple, as are the components used. However the basic principles for building, connecting ports and modeling the interactions between components scale and you are now ready to work with more complex systems and components

Experiments

This is an exercise built to get experience working with the application and getting a feel for how systems work. It can be experimented with, by changing how the door is operated, for example through a PLC.

Currently, the door opens a little bit each time a duck passes the sensor. Can you modify the system to stop opening the door after the first duck has passed?

Add a second sensor and connect it in a way that closes the door instead.

Further Studies

As systems grow bigger, the need for structure increases. Simumatik has developed a set of guidelines and best practices to manage larger projects. How to use the guidelines is described in another academy module and is the next natural step on your way to master modeling in Simumatik.