Models 4 & 5: Parking garage

Is the parking garage full?

Grade level

11-13

Time required

2 double lessons per learning unit (extendable to 10 DL)

Degree of difficulty

Model: light to medium, programming: light to medium

Model Type

Tabletop model for parking garage barriers

Download teaching material

MODEL DESCRIPTION/TASK

The students plan and implement a parking garage barrier for entering and exiting a parking garage.

The request to open the barrier is initially made via a button (entry) or a button on the display of the TXT 4.0 controller (exit).
Two LEDs give light signals when fully open (green) or during opening and closing (red). A light barrier monitors whether a vehicle is in the barrier area during the closing process. The number of free parking spaces is determined from the number of entrances and exits and displayed on the TXT 4.0 controller; the red LED (parking garage 1) flashes when full.

In a second step, two groups come together and connect their models and controls in such a way that one barrier serves as the entrance and the other as the exit (parking garage 2).

In the fully developed model, the barrier control is supplemented by optical licence plate recognition using the USB camera and automatic parking price determination (parking garage 3).

EVERYDAY RELEVANCE

The barrier-controlled access to parking spaces and car parks is familiar to students from everyday life. In particular, automatic access through optical licence plate recognition has a high motivational value. The topic could be integrated into professional orientation with regard to information technology fields. Automated switching by recording physical variables is used here in many areas. In particular, the automated detection of objects in access technology is becoming increasingly important.

Key Questions

Where can an automatic barrier system be used in everyday life? (Communication)
Which functions does the parking garage gate control system have to fulfil sensibly? (Collaboration)
Under what conditions should the system open or close? (critical thinking)
What needs to be considered so that the control can be used at different locations and the system works as robustly as possible? (Creativity)

Subject Reference

Information technology

Advanced programming, condition loops, functions

Mathematics

Angle, conditional counting, time and price calculation

Technology

Stable construction, construction technology

Physics

Movement change

Lesson Plan

Interview (with app)

The procedure for building the model and the functions to be achieved are developed together.
The work steps of the app are specified or discussed.

Partner or individual work (with app)

The students familiarise themselves with the app and load the corresponding task.
The students define meaningful functions of an automatically opening and closing barrier.
The students use the app to create the requirements list for the barrier system to be built.

Optional partner or group work (without app)

Optionally, the students outline the possible structures of the barrier with further sensors (light barrier) and actuators (LED).
The students discuss the results in the group and agree on a design.

Optionally available: Presentation and assignment of differentiation (with app)

Students (or the entire group) that come into question for differentiation are addressed by the teacher if necessary. The combination of two barriers for separate control of entry and exit is presented in group work.
As a further differentiation (or directly after the first program without subsequent group work), the USB camera and the recognition and evaluation of licence plates are offered in the app. The app offers concrete ideas for e.g. time recording and calculating parking fees.

Partner or group work (with app)

If necessary, dismantle the connection of two barriers and continue working in the individual groups
Connecting the USB camera
Handling and decoding the barcode and saving it in a new program
Loading the program from parking garage 1
Design of the display of the TXT 4.0 controller according to learning cards
Step-by-step expansion of the programme: Registration and storage of entering licence plates, calculation of parking time and fees for exiting vehicles
Simulation of the payment process and opening of the barrier, calculation and display of free parking spaces in each case

Optionally available: Presentation and allocation of differentiation

Particularly efficient groups can be given the extension task of storing the incoming electric and normal cars in separate tables and, for example, providing 4 parking spaces for electric cars and 6 parking spaces for N cars. Parking fees can also be calculated on a differentiated basis. Independent work without learning cards is planned here.

Discussion in plenum

Debriefing of the project in the classroom
Clarification of future possible uses in everyday life

Notes and information

Methodological and didactic notes

Differentiation options

Depending on the duration of the lesson series and the strength of the students,

two groups put together their systems as an entrance or exit to a car park,
couple two TXT 4.0 controllers (entry/exit) to synchronise counting results,
they use the USB camera in parking garage 3 to determine the parking time for entry and exit and have parking fees displayed on the display based on the determined data.

Motivational aspects

The topic of automatic barrier systems is familiar to all students from everyday life. Automatic licence plate recognition, which can be transferred
to other automation processes if necessary, motivates intensive discussion and solution of a corresponding task.

Supplementary materials

If available, a video could be used for the introduction phase to the topic.
Drawing media (paper, whiteboard or projection surface).

Installation instructions for parking garage barrier

Wiring diagram for parking garage barrier

Licence plate recognition assembly instructions

Wiring diagram for licence plate recognition

Functions of the model and their technical solutions

Functions of the sensors/actuators	Technical solution
Running an Encoder Motor Rotation	Actuation of the drive motor for exactly one rotation
Red/green LED light signals	Actuation of the LED for free travel and stop
Interruption of the light barrier Interruption of the light barrier	Preventing barrier movement Counting the cars
Licence plate recognition via USB camera	Opening the gate
Parking garage 2: Connection of two TXT 4.0 controllers	Separate control of entry and exit barrier Data exchange between two TXT 4.0 controllers
Parking garage 3: Licence plate recognition via USB camera	Barcode decoding Programming and evaluation of start and end times Calculation of parking fees

Material List

Sensors	Function
1 On/Off button on the TXT 4.0 controller	1. Switching on the barrier control 2. Emergency stop of the barrier
1 phototransistor	Light barrier interruption detection, receiver
1 USB camera	Barcode recognition
1 mini button	Requisition for entry
1 mini button	Status query of the barrier (open or closed)

Actuator	Function
1 Encoder motor	• Movement • Revolution Count
2 LEDs (1 × red, 1 × green)	Status Indicator Light
1 LED (white)	Light barrier sensor illumination