Automating & Educating the World’s Leading Companies

The Challenge  

To create a new test station that would automate and record data for the testing of prototype and  production steering assemblies to ensure the longevity of a key component of the new product.  

The Solution  

Create a new test station using LabVIEW that automates motion control and data collection migrating  from the prior hydraulic valving method used along with hand written data.  

Introduction  

Data Science Automation (DSA) is a premier National Instruments (NI) Alliance Partner that  specializes in automating and educating the world leading companies. Clients choose DSA because of  DSA’s deep knowledge of National Instruments products, disciplined project development process, its  staff of skilled Certified LabVIEW Architects and Certified Professional Instructors, and its unique focus  on empowerment through education and co-development. DSA has long been the leader in mechanical  life testing, working with manufacturers of critical structural components for complex engineered  systems.  

Background  

During the development of a new floor cleaner the manufacturing team needed to test the new  designs for their steering column assembles. The new steering columns needed to be tested to verify  their ability to withstand the normal forces the column would be subjected to throughout its expected  lifespan. This testing would be done in two phases - during the design phase and during the  subsystem manufacturing phase. This would help the manufacture handle any issues before the parts  were installed in the new product. The fixture would also go be used as a quality test system once the  units were in full production to help maintain the level of quality needed to ensure that the product  would not fail during operation.  

Approach  

The older method of testing these type of parts was controlled using hydraulic cylinders and timers  that would need to be manually set for each test. The data was collected periodically by an employee  only on a daily bases. This sporadic testing made it difficult to quickly spot trending toward an  impending possible failure until after the part had actually failed. Using the new test system (Figure 1)  the operator can review the collected data trend by just looking at the screen and observing the  condition of the latest data. This data was also recorded at a much faster interval than the manual recording of data. This resulted in more insight into the failure process than the older method. The  new system used two cDAQ 9174 chassis along with NI 9401 cards to provide eight counters to  control four test stations. Each of the test stations was able to be controlled independently. The  operator could also view all of the data for all four of the test stations on a single screen (Figure 2)  allowing them to make a quick assessment of the condition of the parts and rapidly identify if the  stresses were trending in a pattern of known failures. The LabVIEW software controlled the motor  direction and the degree of turn needed for the testing of the components. The system allowed the  operator to set the percentage of the full rotation and the ratio of full turns to partial turns. This was  to more accurately represent the range of stresses that would be applied to the components as the  floor cleaner was used in a real world environment. The system would monitor and record the  temperature of the power steering motor to insure that it was not overheating during the course of  the testing. All strain gages were also monitored and recorded to make sure that the forces on the  components stayed within the test parameters that would be entered at the start of the test. The RPM  of the shaft rotation was also monitored as additional parameter required to be controlled.  

Benefits  

The new system made it easier for the operator to enter the various set points that determined the  operating conditions and simplified adjustments while the test was in progress. The operator could  pause the test to check components for visual wear if the data showed an early trend toward failure.  This would allow the design team to make necessary adjustments before the test was completed  without losing the data already collected.  

A secondary benefit of the new system was that it would help keep the facility cleaner by reducing the  amount of hydraulic fluid used in the test fixture. The older test system would leak hydraulic fluid from  the main actuators which contained large amounts of the fluid. By reducing the amount of hydraulic  fluid used also helped to make it a greener facility.  

This automated test system was powered by LabVIEW and NI hardware to achieve a better overall  test solution. It provided better insight into design flaws and quality deficiencies prior to full  production. The system plays a major role in the client’s quest to provide higher quality products for  their customers.  

Contact Information  

Richard M. Brueggman, rmb@DSAutomation.com 

Data Science Automation Inc., 375 Valley Brook Road, Suite 106, McMurray PA 15317  (724)942-6330  

www.DSAutomation.com

Figure 1. The New Test System during Initial Installation and Checkout 

Figure 2. View of Four Station Graph Display