Introduction

First, we will work with the actuator, that is, the DC motor.  The necessary connections will be made in the protoboard with the aim of introducing various input values that will allow us to characterize the instrument. To make the most detailed modeling of the device, we will perform and use various other real measurements, as well as theoretical procedure techniques.

Secondly, we will work with the sensor, making all the corresponding connections in a protoboard to activate the ultrasonic pulse used by the sensor to measure the time it takes to reach and return from the nearest obstacle in the direction it is pointing. To measure this time, a handheld oscilloscope will be used, and a simple physical relationship will give us the desired distance, which we can compare with a manual measurement of the distance.

Motivation

Arduino platforms today offer an excellent solution of simple use (plug & play type) for the assembly of a wide variety of automated systems. However, working with a protoboard and signal generators not integrated into computerized systems has enormous value and utility when performing many other assemblies.

Becoming familiar, even at an introductory level, with the connection and the operation of electronic elements at a deeper and more basic level than that offered by more plug&play oriented solutions, such as Arduino, not only has an important didactic and practical value but, in addition, can be extremely satisfactory.

But it is not only about connecting and operating these devices, but also about knowing their principles of operation. Moving away a little from the philosophy “connect, program and use”, which is also so useful, and digging deeper into the knowledge about the operation of these instruments, offers a different and complementary perspective that can be very useful and interesting. Due to the importance and wide application of sensors and actuators in industrial processes and robotics, it is important to know details about their operation.

Objectives

The specific objectives of this practice are as follows:

• Perform the complete connection of a DC servo motor and a sensor on a protoboard.
• Gain solvency in the operation of an oscilloscope and a handheld multimeter.
• Learn about the operating details of an actuator (a DC motor) and a (distance) sensor.
• Characterize and model a DC servo motor, also obtaining its transfer function.
• Characterize a distance sensor whose operation is based on the use of ultrasounds.

Required Material

The laboratory kit you will be working with consists of the following components and instruments:

• The Home Electronics Laboratory Platform (HELP) card, whose main elements, for this practice, are the protoboard, the outputs for the oscilloscope, and the 5 V power supply, with or without switches.
• Hantek’s 3-in-1 instrument, which includes: multimeter, signal generator and oscilloscope.
• The DC engine to be characterized and modeled (a Futaba S3003 in this case).
• The ultrasonic distance sensor to be characterized (HC-SR04).
• The cables needed to make the connections.

Use Case Study

Available at: HELP Case Study – UNED I.pdf

Webinar

Available at: HELP bi-monthly webinar – UNED-20221208_130138-Grabación de la reunión.mp4