Patrick O. J. Kaltjob - Control of Mechatronic Systems

2 1.2 For monitoring and control objectives of the following systems (a–c):electric-driven driverless vehicle with a GPS-based traffic model for trajectory guidance and a sonar-based radar tool for collision avoidance;robot-aided surgery with direct current (DC) motors as actuators for 2D arm positioning, using an advanced laser beam and image processing for thermal-based cutting precision; andintelligent cow traffic monitoring using a solar powered cow collar device with embedded accelerometer;perform the following technical activities:Identify control project objectives and control processing functions.Identify key I/O system and control variables.Identify output variables and classify them as (a) measured or (b) unmeasured;List some safety, environmental, and economic considerations.Discuss the most suitable hybrid control strategy (logic, continuous).Sketch the hybrid control block diagram.

3 1.3 As depicted in Figure 1.14, an incubator is used to keep eggs at a suitable warm temperature and humidity (i.e. the balance of heat over the oxygen level) to moderate conditions in order to induce hatching from embryos to mature chicks. This is done through an automatic egg-turning device by rotating the rack of eggs in order to change their position. During this incubation cycle, the embryos breathe and exchange hot air through thousands of pores in the eggshells.Identify the control project objectives and possible control processing functions.Identify key I/O in the incubator system and corresponding control variables.Identify the output variables and classify them as (i) measured or (ii) unmeasured. Briefly describe how the unmeasured variables could be estimated.List some safety considerations and interlock processes to be introduced as a result.If a pump humidifier and a heater are used to supply water steam while a lamp produces radiation to heat the chamber temperature, draw the hybrid control block diagram.Sketch the possible operator panel with corresponding indicator lights and logical I/O variables. Figure 1.14 Egg incubator schematic.

4 1.4 Heart surgery requires the regulation of patient's blood pressure at a desired value. This is achieved by adjusting the infusion rate of vasoactive drugs into the patient's blood vessels. In addition to the effect of vasoactive drugs, blood pressure is also affected by the level of anesthetic given to the patient.Using control strategies, sketch a detailed block diagram for a hybrid control system that enables the measurement of blood pressure and regulates the infusion rate of a vasoactive drug accordingly.From the resulting block diagram, identify devices that could be used in the measuring and detecting unit and in the actuating unit.

5 1.5 For the following mechatronic devices:millimeter-wave radar for the detection of a surrounding object distances in an unmanned car collision avoidance management system;blood plasma detoxification is achieved through an implanted artificial liver bioreactor. The underlying process is a filtration though a semi-permeable membrane sheet while maintaining a pressure-regulated blood circulation. A user interface is used to remotely monitor the reactor status. This is done despite human body temperature variation;an automatic electric cooking machine with speed and temperature controls combined with monitoring indicators for cooking time and cooking stage, as well as a control panel allowing the selection of spin speed and cooking program; andan automatic vacuum cleaner with a user interface for motion control. It has an antenna to communicate with the base station (remote control), four dirt sensors, each measuring the number of dirt particles, two DC motor-driven wheels, and a steering motor:List their corresponding I/O (logic and continuous) variables.Sketch the hybrid control block diagram.Draw the I/O variables of the control panel (with its user interface) including as much details as possible, such as the ports of I/O devices connected to external circuitry such as sensors.

6 1.6 A robot-based laser beam cutting system consists of two actuating devices: a joint angle motor and a fine piezoelectric transducer for head positioning. A photo-sensor measures the head position and the position error is fed to a separate controller for each actuator. Draw the block diagram for this automated cutting machine. If an optical technology is used for image processing-based feedback to achieve highest precision cutting, update the hybrid control block diagram along with an operator panel (list all I/O variables involved).

7 1.7 In order to design the control system for an electrically-driven dialysis blood processing system, as illustrated in Figure 1.15, a temperature and pressure are monitored from the control panel such that abnormal dialysate pressure outside the −410–+330 mmHg range (avoid exceeding the pressure in the blood compartment) with an accuracy of ±7% triggers an alarm and flashing lights. This is also the case for membrane rupture, which could cause blood contamination. The transmembrane pressure regulates ultrafiltration (i.e. removing toxic fluid).Identify all components of the mechatronics process.List key I/O (logic and continuous) dialysis blood system variables involved.Sketch the corresponding hybrid control block diagram taking into account volumetric and flow sensor controls.Draw a control panel, considering variables associated with the interlocks fulfilling the safety requirements listed here. Figure 1.15 Dialysis blood processing system.Source: Based on Kaltjob P.

8 1.8 A Global Positioning System (GPS) receiver-based autoguided missile has a precision-strike mechatronic system which is used to track a predetermined flight trajectory by regulating the angle between its axis of motion and its velocity vector. The adjustment of the missile angle φ is achieved through the thrust angle ß, which is the angle between the thrust direction and the axis of the missile, as illustrated in Figure 1.16.Identify the flight control processing functions for the guided missile as well as corresponding I/O variables (including GPS position, velocity, attitude, and orientation) and a gyroscope-based stability function using line-of-sight measurement.Draw a block diagram for the intelligent control of the auto positioning system for the missile angle using a gyroscope to measure its angle and a motor to adjust the thrust angle.In the case of a heat-seeking missile, a guidance control strategy is used. How would the control block diagram be modified for this? Figure 1.16 Guided missile trajectory.Source: Based on Kaltjob P.

9 1.9 A crude oil distillation process using a boiler-based temperature control is illustrated in Figure 1.17. The distillation process is used to separate gasoline from asphalt, controlling the reflux rate by regulating the flow of distillate composition at its top and by varying the rate of steam to the reboiler at the bottom. Among the key process variables are temperature (continuous) and flame (binary) in the combustion chamber (boiler).Identify the control and monitoring objectives of this distillation process.Identify all devices involved in the distillation column temperature and flow process control and their corresponding I/O variables.Sketch the block diagram for continuous pressure control, feed control, boiler temperature control, and reflux control of this distillation process.List key possible I/O (logic and continuous) variables involved. Draw the corresponding hybrid control block diagrams. Due to the multifunctional controllers required, it is desirable to have a DCS architecture with SCADA network.Sketch the DCS schematic linking all required type of field control devices, data acquisition unit, and a local control unit up to the central command and control unit.Sketch the schematic of the control panel and visualization system for this distillation system plant containing the execution unit of the management information system functions along all logic control connections. Figure 1.17 Schematic of a crude oil distillation process with its boiler temperature control system.Source: Based on Kaltjob P.