Challenges and Best Practices for Implementing a Test Cell Control System

Transcription

1 Challenges and Best Practices for Implementing a Test Cell Control System

2 This presentation will cover some of the key concerns and trends with test cell control applications along with some best practices and recommendations for how to solve them.

3 Agenda Definition Project Management Specification Overview Details on: o o o o o o o o Facility Safety Hardware Software Mechanical Electrical Software Data, Reporting, Remote access 3

4 Definition of a Test Cell A TEST CELL is a defined space, whether a brick and mortar room, modular room, or singular enclosure on the production floor or an enclosure Integrated into a production line. A TEST CELL includes the following key considerations: Requirements of the cell itself (Purpose) Safety Factors Operator interaction with UUT Throughput Maintenance/Reliability/Uptime/Downtime Requirements of the UUT Facility Requirements MRP / IT Requirements

5 Specifications THE BIGGEST CHALLENGE WE FACE! We work on projects where the specifications range from a blank sheet of paper, to a document full of inaccurately defined and incomplete information, to reams of boiler plate information where not all information supplied is required what's really required. A well defined specification will ensure: Risk mitigation Vendor alignment with overall goals Timely delivery Reduced cost (both initially and during the project) Commonality across bidders (ensures everyone is bidding to the same requirements if the intent is to outsource). Achievement of the goals of the system. A system that isn t under defined or over defined wants vs. needs! Is the system defined to meet both the requirements of the test cell control and the test requirements of the UUT?

6 Specification Development ARE YOU WILLIING TO INVEST IN THE DEVELOPMENT OF A SPECIFICATION? Internal Development: Resources available internally? Time to dedicate to clearly define the requirements of the system, and still get your daily requirements accomplished? Experience and the expertise to define the requirements of the specification and ensure that the test cell is defined and the UUT requirements are defined? Input from all the stakeholders? Technology is changing at a phenomenal rate have you accounted for this in your definition.

7 Specification Development Continued Are you defining to a budget or defining to a goal? Are you upgrading a system or building new turnkey? Are you tying into sub-systems and what protocols for communication are available, will this change? Is a facility layout defined and the limitations of the existing space called out? Are all UUT test requirements defined? (Part Prints) What facility utilities are available and how does this change your equipment definition. Are there specific documentation requirements? Do you need to meet standards or specific regulations? (FDA, ITAR, EAR, UL, EU, CSA)

8 Specification Development Continued Will this system require long term data storage or integration with plant systems? Will this data need to be mined overtime? What is required for reporting, does the report need to meet a specific format? In the end whether you are willing to invest in the development of a specification or not either with internal resources or external it will cost you! It will also be the most important aspect of your project!

9 Project Management Can make or break a project! How is the project to be run - agile project management, T & M, fixed bid There should be design gates that ensure that the project is being executed correctly. The following are the gates that WTI uses: Kick-off PDR User Screens reviewed and software specification agreed upon CDR - acceptance test plan needs to be defined and agreed upon all mechanical and electrical prints reviewed and agreed upon. Run-off and availability of parts When are components ordered for timing consideration and long leads. Schedule part suppliers make commitments and then miss them this is outside the suppliers control

10 What is the goal of the Control system? R & D highly flexible geared to high level engineering use? Life Cycle Durability long term testing of the same product or family of products. Component DV\PV product performance criteria and validation to meet design intent typically requires parametric values. Electromechanical and Electronic in most cases have very different needs. Production high through put go/no go, safety related UUT s and those for critical operations will often include long-term storage requirements and safety requirements. In all cases the life of the tester needs to be considered as well as if there is a specific product that will change over time, stay static, a range of products, different products, or will the system be deployed over multiple cells or different locations.

11 Control System Hardware Selection Criteria Wide range of criteria when determining hardware for any control system, many of which are dependent on the type the goal of the organization, accepted practices, requirements of the UUT, and how the data is to be handled. Goal should always be to utilize COTS equipment. PC-based with Windows OS doesn t require precise execution timing or determinism (an event takes place at the same time every time without fail whether it s a millisecond or microsecond). Blended System combination of PC, PLC, or Real-Time; in many cases it is dependent on the goal of the system as well as it can vary dependent on each companies accepted practices. Company methodology some call for separate safety hardware from the control and data acquisition. Real-time where determinism is required or the safety systems are to be integrated with the control and data acquisition system. Distributed I/O inputs and outputs need to be placed in a variety of locations yet be integrated in with a master controller.

12 Control System Hardware Considerations Wide range of considerations when determining hardware for any control system. Vendor selection is CRITICAL! Is there a need for custom PCB s? In some cases the products just don t exist to accomplish the task. Can the PCB be replaced with an FPGA? Are there company product standardizations to be considered. Is there a frequent need to change I/O or add I/O. Will the system configuration grow or change. Experience with the platform. Required accuracy of the data. Acquisition rate required and the channel density and type. Support, serviceability and calibration requirements. Where is the hardware going to be deployed. Requirements for up time.

13 Safety Requirements One of the factors given the least consideration yet it remains the most important both from the standpoint of personnel safety as well as the safety of the equipment and the UUT! Safety Considerations: Guarding Fire suppression E-stops hardwired safety devices Door Interlocks Watchdog timers Defined procedures for different shutdown requirements NEMA ratings and requirements for explosion proof ratings (intrinsic barriers). Lock-out / tag-out requirements Sound Attenuation High pressure fluid(zero Potential Energy) Hazardous gases or fluids Fluid containment Local codes and requirements

14 Mechanical Consideration needs to be given as to whether there are mechanical requirements to the cell. This topic will focus on the mechanical considerations that impacts the controller and the accuracy of the data acquired. What are the required components and performance specifications? High Speed, Torque, load, pressure, flow.. May require specialized maintenance equipment, custom designed parts, or specialized equipment for set-up. 4x/10x measurement accuracy These requirements will drive cost How accurately do your Process Variables need to be controlled and measured. How frequently do you need to change out the fixturing/tooling? Does the cell require vibration isolation or monitoring for predictive maintenance or alarming. Are these requirements attainable?

15 Mechanical Design Assembly Tools What data do you require during the design phase to ensure that the mechanical design will stand up to the requirements? Design and Validation Tools Autodesk Inventor 3D Import/export ProE Catia Step Etc. ANSYS Structural (modal, static, rotor dynamics, thermal analysis) Laser alignment Portable CMM Vibration analysis

16 Mechanical Design & Analysis Examples

17 Facility There are numerous considerations when considering test cells in and of themselves. There are a variety of considerations applicable to the control system. Purpose of the test cell (i.e. dyno, servo-hydraulic, HiL, or custom) Placement of the controller, internal to the cell or external cooling or heating for the control enclosure Single client or multi-client Wiring how far are the runs and how big is the cable bundle Separating power from signal wiring Proximity of hardware items that may induce noise into the system Sensitivity/accuracy of the measurements Location and placement of integrated subsystems Test cell requirements heating & cooling (environmental chamber), viewing ports or windows, access ports Main fused disconnect provided? If fuel is required, is a farm needed? What about a cooling tower or existing cooling capabilities?

18 Electrical Electrical as it fits into control plays a significant role in the successful operation of your test cell control system. Power requirements Voltage/current/frequency/grounding and electrical noise Designed to ensure separation of power and signal components and wire routing. Do you require panel to be designed to handle a specified amount of spares? How often are the electrical connectors to be inserted or disconnected to the UUT. Installation Requirements Signal Integrity how do you plan to isolate AC/DC Who is going to handle the installation? Equipment removal? Special Considerations If the system is a controls retrofit What components are you reusing? What documentation is available? How do you manage risk and warranty? Troubleshooting and Maintenance requirements Are all wires and major components labeled for easy trouble shooting. Are components labeled for easy identification? Documentation requirements?

19 Software Ultimately the software is the heart and sole of the system. It provides the user interface, monitoring, profile generation, control set-up, and a host of other capabilities! In the end if the users are happy with the software interface, flexibility, stability, intuitiveness, and functionality of the system, most other issues can be over come. In short if the operators don t like the system it wont work! Our standard is for the deployment of software that doesn t require the end user to access source code to make changes but to manipulate menus. No one solution fits all but NI has the platforms to solve the test requirements; with integration native to the hardware platform or availability of drivers and the ability to create custom devices, and define the functionality of FPGA s. Included software reuse in your project planning. In general our solution of choice for test cell control and data acquisition is INERTIA TM added onto NI VeriStand TM. VeriStand provides a base line COTS software platform that handles all the low level programming, yet gives you access to API s and menus to adapt and customize through menu selections. VeriStand supports model based control!

20 Software Custom devices are available that allow integration of non-supported devices, integration of FPGA s, custom protocols, and the direct importation of models for model based control. Programmed with in the supplied templates all channels become native in VeriStand and accessible throughout the menus available in VeriStand. INERTIA a custom add-on that includes a suite of tools for complex control algorithm development, PIDF tuning, profile previewer, and a profile editor adapted to dynamometer, servo-hydraulic and custom test stand requirements, and custom step creation. Custom LabVIEW can be easily integrated into VeriStand enables the creation of custom features and add-ons for non-supported devices or if custom user interfaces are required you have complete access to the API. Custom LabVIEW can also be a cost effective choice for many custom one off machine applications as well as test cells and production applications, ensure source is provided and is documented (keep in mind this adds cost). VeriStand can also be deployed on PC based solutions. Calibration utilities are standard. VeriStand and INERTIA provide the end user with the functionality and advanced programming features to ensure scalability, support, and long term compatibility to ensure that your systems are current and stay current without losses in capital.

21 Data, Reporting, Remote Access The final piece in the consideration for a test cell application is ultimately the data it creates and what you want to do with it? Will the information be communicated to a server this will typical require an intermediate PC so the server isn't pinging the tester. How much data needs to be maintained on the test system. Is their a plan in place for archival or will it be a FIFO. The hardware and software platforms discussed all provide for TDMS data output. TDMS is compatible with a variety of analysis tools including EXCEL, Diadem. Templates can be created in Excel and automatically populated. Diadem provides an extremely powerful tool for scripting, analysis, data mining, and reports can be created for virtually any requirement and provide for the creation of SPC capabilities. Remote access is possible to allow customers or lab personnel to access the stands remotely to check-up on the status of tests, respond to alarm conditions and shut downs hardware can be added to provide cellular contact to provide notification of cell conditions. And test results can be served to a website to allow others to access and view data.

22 Control System Examples Engine Dynamometer Cell for ECU R&D for implementing proprietary technology to increase fuel economy on combustion engines. This application represents a turn-key development from the bedplates on up by WTI.

23 T Dynamometer Installed From Concept..

24 T Dynamometer Installed To Design

25 T Dynamometer Installed To Implementation

26 Linear Actuator Test Stand The actuator test stand is designed to provide forces in excess of 120 kips at rates as high as 2ips utilizing a servo hydraulic loading system to test the UUT. Sensors will be provided for measuring actuator position, load, and cylinder port pressures

27 Control System Upgrade

28 Control System Examples ATLAS Lab at Lehigh University 2 nd largest structural engineering lab in the world.

29 System Examples This system was designed to measure the diameter and crown of rollers that are used in the paper pulp industry. The rolls vary in length and diameter from in length, and 4 28 in diameter. The laser micrometers will have a resolution of 0.1 micrometer and a linearity of +/- micrometer. This system achieves accuracy of better than inches dependent on both temperature and vibration.

30 System Examples A supplier of high quality engine and transmission oil pumps required a developmental test stand that would operate the samples in actual use conditions. This included various oils at various temperatures and the ability to input controlled RPM input profiles, delivery pressures, and pressure drops across the part to the samples under test. By applying our INERTIA software and National Instruments PXI real-time hardware for control and data collection, we executed a complete turnkey solution capable of offering 1 PSI pressure control throughout the test sequences. This tester utilized gain scheduling multi level PID control (an important feature of our INERTIA product) to provide the rapid response and precision control of the pressures required while also controlling all other key variables during the test.

31 System Examples WTI was contracted by MSU to deliver a state of the control and data acquisition system for a 6wd independent electric motor per wheel dynamometer system. Our INERTIA system was selected and is capable of independent control on a per wheel basis allowing dynamic control of each dynamometer in three modes: torque, speed, or model based control. Any Matlab based model environment can be used; however, in this case, the customer chose to utilize TruckSim for the simulation mode.

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