Functional Testing & Analysis
Integrated Solutions for End of Line Testing
The quality of assembled products is an important key to a manufacturer's success. A-Tech Instruments Ltd. provides a number of solutions for "End of Line" testing. The measurement of product functionality is typically performed by measuring various physical characteristics. Measuring this functionality at the end of the assembly process ensures proper assembly, 100% quality checking and ensures that “bad” product does not get to the customer. The effort to move an arm on a hood hinge, the current a motor requires to move a component, the torque required to move a lever are all measures of the products assembled fit and functionality.
Information about the assembly process as well as the final quality and functionality of the product can be gathered through measuring various characteristics of an assembly. The integrity and tightness of a rivet will be revealed in the torque required to move an arm. The quality of an extruded roll formed seat rail will be seen in the ease and smoothness of the rollers running through the track. These measures not only ensure that the final product is functional but provides feedback for upstream processes.
Various types of sensors and instruments can be used for functional testing. The vast variety of sensors that A-Tech Instruments carry allow us to select the most appropriate sensor to perform a particular measurement. Understanding sensor theory and practical implementation principles benefit the proper selection of sensors such as load cells. Multi-function sensors such as the Burster 8661 with integrated quadrature encoder allow the measurement of torque and angle with the same sensor. Non-contact displacement sensors such as laser sensors allow for measurement of motion without interfering with the component under test.
A key element in functional testing is the ability to test the product in a state that most closely mimics its real world environment and conditions. Sensors can be chosen that can withstand harsh environments and extreme temperatures.
The wide variety of instrumentation allows for testing at different levels depending on the complexity of the test as well as the type of data to be gathered and reported. Many functional testers are used as a tool in product design, development and continuous improvement.
Burster Digiforce 9307
The Burster Digiforce 9307 is a full featured analysis system that goes beyond standard X vs. Y signature analysis with tolerance bands and windows.
What makes it different?
A feature rich instrument that can accept multiple inputs is the Burster Digiforce 9307. This instrument accepts a wide range of sensor types and plots graphical information such as torque vs. Angle, Load vs travel, current vs. load, vibration vs. time. The instrument has many evaluation techniques such as windowing, tolerance bands and cross data calculations. It has the ability to run multiple programs and can switch from one test to the next very quickly. This instrument is an ideal end of line tester that gives quick immediate feedback of product functionality. Data can be serialized and stored for future reference or SPC analysis. A-Tech Instruments has integrated this system into many end of line scenarios, providing sensors, cables and commissioning assistance.
Inputs
Voltage, Strain gauge, Potentiometer, Encoder, Piezo, Milliohm
Evaluation
The 9307 features a number of Evaluation techniques including cross channel calculations and complex windowing .
Standard Windows, Trapezoids, Thresholds, Envelopes
Reporting
Data collection and control through USB, Ethernet, Profibus, Ethernet IP, Ethercat
Fast and Powerful
10,000 samples per second, 10,000 data points, up to 128 programs, lightening fast evaluation
Burster Solution Delivered!
The following application used a Burster 9307 with Ethernet IP to monitor an End of Line tester. A Burster 8661 torque transducer along with a current shunt were used to measure the torque and current generated by the component. Encoder pulses, Time of actuation and Voltage were also measured.
Equipment Diagram
The unit under test was a motor/gearbox/brake assembly used as an automatic actuator in an automobile. The motor drove through a gearbox and brake to open and close a door. The brake is used as a stopping mechanism to hold the door at any desired location and as a safety stop. The system also has an integral encoder to monitor position.
The 9307 monitored all of these parameters as the system was taken through a number of test sequences. The entire End of Line tester relied on feedback from the Burster 9307 to determine the pass fail condition of the part. The station used a total of 6 programs (3 left hand, 3 right hand). Tests were selected through the PLC and switching form test to test occurs in Milliseconds. The data was also collected into the Burster DigiControl software so that data could be reviewed and analysed. Ethernet IP was used to collect specific data from the test so that it could be collected with other serialized information.
Encoder Test
The encoder test checked the correct operation of the internal encoder. The Burster 9307 has an encoder input channel that measured this parameter directly. Collecting data on a time base allowed for a measurement of travel vs time.
Encoder Test : X - Time Y1 - Encoder
- Encoder counts in correct direction to correct number of counts in 4.000 secs.
- Stable output (stays within trapezoid)
- Signal on Phase A and B if not counts will not be correct
- Correct phase shift or direction would be reversed
Actuator and Motor Testing
The motor test checked that the motor functioned correctly under load. A servomotor was used to provide resistive load to the motor/gearbox assembly. The Burster 9307 has the capability to measure two Y axis simultaneously. In this case the first channel was used to measure torque vs positon, the second channel monitored Current vs positon.
Motor Test : X - Displacement Y1 - Torque Y2 - Current Linear Electric Actuator
- Torque Indication is maintained within the window
- Current stays within tolerance
- Speed is derived as a function of distance traveled before test is stopped at 3secs
- Torque is measured and graphed
Accelerator, Brake and Clutch Pedal Testing
The brake is a variable brake that uses a variable voltage to increase and decrease the amount of braking applied. This test used the torque sensor, a voltage input and current sensor to monitor Torque vs. Input voltage and Current vs. Input voltage.
Motor Test : X - Brake Volts Y1 - Torque T2 - Current Clutch Pedal
The Burster 9307 system is an economical test platform that allows complex testing to be performed
without the need for custom programming and complicated data acquisition systems.
Rapid “End of Line” Test Systems
Our Universal Test System Platform have been developed based on application demands and over 30 years of input from integrators and end users. The fundamentals of these systems is the integrated hardware and software platform combined with the ingredients necessary for application execution, namely Deterministic Measurements, Digital Communication, Real Time Signal Processing, Closed Loop Control, Integrated Graphical User Interface, Data Computation / Analysis and Data Reporting.
The Closed Loop Control encompasses Digital and Analog Outputs, as well as Data Commands using field buses like CANbus, LINbus, RS232/485, Ethernet-IP, Ethernet-UDP, Ethernet-TCP/IP, etc.
Other functions available are Leak Testing, Weighing, Torque to Turn, Assembly Force, etc., can be incorporated with the data. The integration with Barcode Scanners, Vision Systems and other peripherals is possible, with the range of tools available.
HVAC Graphical Display shown, up to 6 Servo currents, Blower current, Sound & Vibration.
imc C-SERIES
Some functional test equipment such as the imc data acquisition and control systems have the ability to control the test as well as measure and gather data. These systems often use feedback from the test parameters themselves to control the test.
The imc C-SERIES system is a highly flexible system that can accept multiple sensor inputs. It is expandable to channel counts in the thousands. The on board processor allows for complex data processing such as FFT and Spectrum analysis in real time. The high speed processor provides for real-time calculations and outputs for feedback and control of the process. One instrument can command actions through CANBus messages or analog PID circuits and collect and analyse the data in one expandable system. The easily configured software package makes setting up and running tests easy and flexible. This system excels in testing situations that require complex control or analysis as well as in applications were multiple parts are tested simultaneously. A-Tech Instruments has integrated the imc data acquisition and control system into many “end of line” scenarios. It is also used in compliance testing, simulation and endurance testing in aerospace, power generation and research applications.
Because of the high level of processing and flexible I/O configurations the imc data acquisition and control system can be used to not only measure the various parameters in a functional test but it can also be used to control the test based on pre-set test functionality and on feedback from the test parameters themselves.
imc Solution Delivered!
This application used an imc C-SERIES system to control and monitor a multi part test fixture. The system was used to monitor the functionality of bearings on an automotive component as they were taken through life cycle and endurance testing. The tests were extended tests that exposed the parts to varied run conditions, speeds, acceleration and decelerations and environmental conditions. The tests were to be performed with a specific profile that would emulate real world conditions. The tests would be performed at an accelerated rate to push the components to their life cycle limits.
The imc C-SERIES was selected because it could not only measure all of the physical parameters but it could also control the tests and execute the profile that was to be followed. The system used CanBus communication to command a servo motor to run the components through a serpentine belt. The speed and acceleration were all controlled by the imc system. The temperature of the bearings on each part was monitored for any alarm conditions. A force measurement was used to measure the force on a belt tensioner that was used to load and unload the system. This force measurement along with an analog output was used in a PID loop to control the belt tension dynamically.
The processor in the imc system runs a profile of various speeds, tension and temperature. While the test is running all temperatures are monitored to see if any bearings are beginning to heat excessively.
Various conditions will trigger different events from increased sampling, operator notification or complete shutdown. A comprehensive visualization package provides an easy to read display with graphical displays and touchscreen functionality.
The imc C-SERIES allows for monitoring of all I/O including the digital I/O used to control the test machine
A key factor in the success of this product is the ease of configuration. The system uses a visual based configuration technique that allows quick page setup and a variety of graphical displays. The Studio software allows the user to easily configure the steps that take the system through the test and react to changing conditions.
The imc C-SERIES system is a flexible and versatile system that can be effectively utilized in all test situations
from end of line testers to development and endurance testing.