Prof. J. Espinoza y D. Sbarbaro 2ndo Semestre 2019

Universidad de Concepción Facultad de Ingeniería Depto. de Ingeniería Eléctrica

Sistemas de Control - 543 244

Desafío 2019: Control de temperatura usando Arduino El desafío consiste en implementar un control de temperatura usando un micro controlador Arduino, como se muestra en la Figura 1, usando Matlab o Python (con Jupyter)

Figura 1. Sensores y actuadores conectado a un sistema Arduino Actividades A. Configurar del sistema B. Modelar la dinámica del proceso con un y dos calentadores C. Estimar de parámetros del modelo D. Control en lazo cerrado: D1. Realizar el control de una temperatura como se ilustra en la Figura 2: sintonización de un controlador PID D2. Realizar el control de dos temperaturas: proponer e implementar una estructura de control

Figura 2. Sistema en lazo cerrado

University. Companies such as APCO, Inc. have devel-oped commercial software for the TCLab into SimTunefor training on industrial controllers such as Allen Bradleyand Honeywell PID control (SimTune, 2019). Universityinstructors share open access teaching resources that rein-force topics such as:

(1) Step and doublet testing.(2) First order (time constant, gain, and dead-time) and

energy balance models as shown in Figure 5.(3) On-o↵ control.(4) Simple feedback structures such as PID (see Figure

6).(5) Feedforward and cascade control.(6) Higher order modelling.(7) Machine learning.(8) Relative gain array pairing.(9) Stability analysis.

(10) Advanced modelling techniques (e.g. recursive leastsquares) and state estimation.

(11) Multivariable control.

Fig. 5. Empirical first order and energy balance modelperformace.

Fig. 6. PID control with the TCLab in Simulink.

The equipment plugs directly into the USB port of acomputer and has a separate power source, again takenfrom a standard USB power unit. The USB power supplyshould not taken directly from a computer USB 2.0 portas this does not supply enough current. A USB 3.0 orUSB C port does supply su�cient current but the heaterpulse width modulation (PWM) causes a fluctuation insupply voltage that produces noise for the temperaturereadings. Using the 5V, 2A power supply for the heatersis recommended.

4.1 Equipment outline

In brief, the system is a simple multivariable system with2 inputs (heating power to two separate heaters) and2 outputs (temperature measurements at two di↵erentpoints). The characteristics are close to first order and thusideal for supporting the learning of introductory dynamicsand feedback. Also, the interaction is mild enough so thatSISO control is e↵ective while significant enough to benoticeable and thus form an introduction to multivariableissues.

Matlab and Python GEKKO Beal et al. (2018) codetemplates are provided for many of the obvious learningoutcomes so that students do not need to be proficientprogrammers in order to implement any changes andexperiment designs to suit their own needs. They do ofcourse need to know elementary Matlab/Simulink and/orPython, but by elementary we really do mean just 5-10 hours experience so that there is an understandingof variables and loops. More details, video instructions,resources and so forth are available at:

• Overview: http://apmonitor.com/heat.htm• Python Package: https://pypi.org/project/tclab• Control Design: https://youtu.be/Mbx5IMICS Y• Advanced Control: https://bit.ly/2DcyBWl

4.2 Main challenges in usage

The students in the authors’ department are comfortablewith Matlab but do not know Python. As the equipmentincludes an Arduino, it is necessary to add the Arduinotoolbox to the Matlab search path and therefore thistoolbox needs to be downloaded.

• For an ideal plug and play scenario the required Ar-duino toolbox should be available on university net-worked machines. However, as this Arduino toolboxis provided by an independent party and not Math-Works, it is not included on the university computersystem Matlab implementation. It took significantdiscussions with MathWorks sta↵ and some ingenuityto find a work around that is satisfactory on theShe�eld network, but even this requires students todo a manual setpath statement to an obscure direc-tory each time to make the hardware work.

• Students wishing to use the hardware on their per-sonal computers would need to install the Arduinotoolbox themselves and this may require softwareskills beyond expectations for the cohort at the placein the curriculum where the hardware is most wanted.

Another obstacle is that the power supply componentsprovided by the supplier do not meet UK safety standards(US power supply with a UK plug converter) and thushad to be replaced with a single 5V USB UK powersupply. Figure 7 shows the replacement power module.Also, the underlying Arduino unit has many electricalterminals exposed which could increase danger of shorts ifplaced on the wrong surface; technical sta↵ in the authors’department decided this should be shielded with a perspexblock.

Prof. J. Espinoza y D. Sbarbaro 2ndo Semestre 2019

Condiciones generales

• Se puede desarrollar en grupos de 2 personas • Máximo 3 grupos • Se debe entregar informe final con el desarrollo de todas las actividades, un ppt y

video. Fecha de entrega límite: 20.01.2020 • Reconocimiento:

o Contra entrega de documentos y como reconocimiento de la actividad realizada se podrá quedar con el set-up usado.

o Si se entrega un informe parcial con B, C y D1 antes del 29.11.19 se evaluará como si fuera la tarea no. 3

• El grupo deberá devolver los materiales si: o no entrega un informe de avance 29.11.2019 o no entrega informe final el 20.01.2020. o decide no continuar con el proyecto.

Postulación y Selección • Postulación: Mediante envío de e-mail a los dos profesores indicando los

integrantes e interés en el proyecto (hasta el 27 de Septiembre) • Selección: Si hay más de tres postulantes se considerará para la selección un

promedio simple de las notas en SLD y de la T1 de SDC de ambos integrantes. Se les comunicará la decisión por e-mail el día 30 de Septiembre.

Más información sobre el sistema: • https://www.youtube.com/watch?time_continue=1012&v=aPoef-6ZaSs • https://apmonitor.com/pdc/index.php/Main/ArduinoControl • http://apmonitor.com/pdc/index.php/Main/ArduinoTemperatureControl