Laboratory Development
CATERPILLAR ELECTROMECHANICAL SYSTEMS LABORATORY
Caterpillar Inc. of Peoria Illinois has agreet to sponsor the development of an interdisciplinary laboratory within the College of Engineering. The broad vision of this laboratory is to undertake a novel approach to University research and education in the field of Electromechanical Systems. Most of the work presently being done in this area focuses on individual electromechanical components. These efforts have spawned the term "Mechatronics" to describe them. Mechatronics, as it is presently thought of, describes the interface of mechanical elements with digital computational power to develop a smart device. Much of the present University activity centers on the design, interface, and control of these individual components. The coordination of several different components has not received as much attention. The Systems approach that will be taken in this laboratory will focus on the individual components as well as the interconnection between different components.
Caterpillar designs and produces a very complex product. Part of the vision is to develop machines that have some level of intelligence built in. To do this, several components of the machine have to communicate with each other and coordinate their activities to get the most out of their available resources. As an example, consider the engine which provides the power to the whole machine. That power is used by the transmission/drive system, the implement system, steering system, cooling system, etc. A truly intelligent machine would have the ability to coordinate the demands of the individual subsystems so as to make maximal use of the engine output. Conversely, use the minimum amount of engine power (fuel efficiency) to complete the necessary tasks. Finally, this must all be done in a manner that is transparent to the driver and does not compromise the performance required. It is this type of system integration approach that will drive the education and research in the proposed CAT Laboratory.
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The plan for the Lab is to design, construct, and analyze multi-component systems that have diverse, interconnected elements. To emphasize the Systems approach, these experiments will be composed of subcomponents that operate in different media. In reality, a CAT machine has components that are thermo-mechanical (engine), hydraulic (transmission/implement), electronic (valve drivers), and mechanical (linkages). The importance of this diversity will be emphasized in the EMS Lab.
The emerging laboratory will be novel. The educational benefits are going to be applicable to a wide range of students and courses throughout the UIUC College of Engineering. Presently there does not exist the capability to demonstrate component interdependency effects on overall system behavior in any of the existing facilities; particularly from a system theoretic point of view. This is true of most, if not all, other universities across the country. The educational aspects of the Lab would give UIUC students a distinct advantage when they go to industry. In addition to the educational aspects, the Lab would also open up interesting and fruitful research endeavors. An obvious area would be powertrain system dynamics, modeling, simulation, and control.
A Fluid Power Laboratory for Undergraduate Education
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The problem being addressed by this laboratory development is the perception by industry that graduating engineering students are missing a vital link between theory presented in the classroom and actual industrial problems. Most graduates who start in the area of Force or Motion control are not able to make a design choice between Electromechanical, Pneumatic or Hydraulic devices as a method of system actuation for a given problem. Thesses three areas of system actuation are known as the Tri-technology areas. Many industrial employers acknowledge that most students obtain a high degree of analytical expertise but are not as advanced in applying these analytical techniques to "real world problems." The objective of this effort is to develop a unique laboratory aimed at given engineering students a unique, hands-on experience with classes of "off-the-shelf" industrial devices. This facility will allow students to directly tie analytical classroom theories with truly practical experiments.
The scope of the intended lab audience will be interdepartmental and include freshman demonstrations of the technology through senior level design projects; undergraduate independent research as well as graduate research and instruction. The impact of this lab will be the development of engineers able to make intelligent design choices between the available "Tri-technologies" and implement them in practice. These engineers will have a solid grounding in both theory and the relevant applications.
The Fluid Power Laboratory at the University of Illinois, Urbana-Champaign is a unique educational facility the has been, and continues to be, developed through a synergistic combination of Governmental, Industrial and University efforts. The laboratory was established to enable engineering students to gain educational experience with off-the-shelf commercial devices that are crucial to modern industry. The use of Fluid Power as an actuation device occurs in such common devices as automobile power steering or brakes, aircraft control surfaces, as well as manufacturing presses or molding machines. The driving motivation behind the laboratory was the fact that few, if any, engineering students ever come in contact with these devices although they stand a good chance of working with them after they leave the university.
The laboratory is housed in the Mechanical Engineering Laboratory and is part of the College of Engineering’s Controls Laboratory system. The lab has been developed primarily with the joint support of the National Science Foundation and the Parker Hannifin Corporation. The NSF program responsible for this undertaking is the Division of Undergraduate Education’s Instrumentation and Laboratory Improvement (ILI) program. Parker Hannifin has contributed via cash gifts from the Parker Foundation as well as equipment donation and very valuable engineering assistance.
The laboratory consists of hydraulic and pneumatic test systems that are interfaced to a computer for automated Data Acquisition and Control. The focus of the lab activities is to support classes related to Modeling, Analysis, and Control of Dynamic Systems. At present these courses span the sophomore through senior levels of engineering. While the facility is physically housed in Mechanical Engineering, most other departments in the College have access to it through the College Controls Lab system. The laboratory exercises give students the opportunity to tie theoretical classroom concepts with practical, hands-on experiments to gain a more thorough understanding and appreciation for the material.
The experiments in the Fluid Power Laboratory are designed to expose students to the rich and complex dynamics associated with Fluid Power devices which consist of both hydraulic (or fluid based) and pneumatic (or gas based). The main source of hydraulic power is generated by the Electrohydraulic test bench designed by Parker Hannifin. The bench consists of the following
(a)A fixed displacement, 1 horsepower gear pump capable of delivering 3.5 gallons per minute of hydraulic fluid at 500 psi. This gives the students a working power supply which is large enough to be realistic but not so large as to be very dangerous in the hands of a beginner. Of course, students operate the machines under constant supervision.
(b)The pump can be used to power the motion of a small 6 inch stroke cylinder. The cylinder’s motion is monitored by means of a linear potentiometer.
(c) The pump can also be used to drive a hydraulic motor. The velocity of the motor is determined by a magnetic pulse pick up, similar to those found in automotive applications for giving wheel speed or engine rpm’s. The frequency of the magnetic pulse is converted into a rotational speed.
(d) The modulation of the fluid to either the cylinder or motor actuator is governed by a valve. This valve then dictates the motion of the ‘actuator.’ There are several valves mounted on the trainer stand itself including a manual directional valve, an electronic ‘on-off’ solenoid valve and a proportional valve.
(e) In addition to the valves located on the trainer stand, there are several other types of valves that can be connected, via the quick connections, to either the cylinder or motor or both. The quick connections allow easy and flexible reconfiguration of the hydraulic circuit. Some of the available valves include
Each valve has it’s own amplifier and driver card that can be interfaced to the computational facilities.
(f) Most of the valve driver boards come with on-board analog electronics. This gives the instructor the flexibility to perform either (i) digital data acquisition and control or (ii) analog control with digital data acquisition or (iii) analog data acquisition and control via an oscilloscope.
(g) In keeping with its theme, the Fluid Power laboratory also has experiments in liquid level control. This allows students to examine multivariable systems with interactions between separate components. This experimental setup demonstrates a classical two tank system.
(a) The computer interfacing is one of the keys to the Fluid Power laboratory. It enables the students with the ability to "visualize " the dynamics of the systems by examining data obtained through the Data Acquisition hardware and software. The computational burden is carried out by a Dell 200 Mhz Pentium computer. Each laboratory station is fully staffed with the necessary power supplies, function generators, oscilloscopes, multi-meters, etc.
(b) The interfacing between the computer and the physical experiments is performed using WinCon, a Windows-based real time data acquisition and control program made by Quanser Consulting. WinCon is fully integrated into Matlab’s Real Time Workshop and Simulink toolboxes making interface programming relatively simple. All of the C-programming that would be necessary is automatically generated by the click of a mouse. To further streamline the interfacing process, Quanser’s Multi-Q data acquisition boards are used as well.
(c) The physical analog and digital signals are transferred via the custom made MW-2000. This is a collection of interface hardware that has been sleekly integrated into an educational laboratory quality package. The MW-2000 contains power supplies, signal conditioning modules, opto-isolators, modules for converting signals from voltage to current, slave relays for boosting digital I/O, and encoder boards, as well as a host of other electronic necessities for the Laboratory. We are proud to say that the MW-2000 was designed and built solely by students of the University of Illinois.
Further details on the Fluid Power Laboratory can be found in the presentations given during the annual lab review at Parker Hanninfin
1.) Lab Review 1999
2.) Lab Review 2000
