- Please refer to the photo gallery to see pictures of the sensor right side up and upside down, as well as the test rig used.
- Remember to check all tabs within excel worksheets. There may be several sheets within each document.
- Initial Sensor Testing
This test was performed the very first time using the sensor. It does not measure anything specifically. The graphs show static measurements for roll, pitch, and yaw.
- Warmed Up
Tests A-1 through A-3 were done without the final code which accounts for the drift in the yaw measurement. These tests show static measurements for all directions, with being able to see slight variations in angle measurements when sitting still.
Tests A-4 through A-6 were done with the final code accounting for the drift in the yaw measurement. These tests show changes of 5 degrees in the pitch and roll directions respectively and changes of 10 degrees in the yaw direction, while the sensor was on the test rig. From the graphs you can see clear changes in angle with little error.
- Not Warmed Up
Tests A-7 through A-8 were done without the final code which accounts for the drift in the yaw measurement. These tests show static measurements for all directions, with being able to see slight variations in angle measurements when sitting still. The sensors had no warm-up time before they were used to test.
This is a statistical analysis of the sensor accuracy based upon data collected from both our sensors, and the sensors used at the Nazareth Clinic for the Spine Simulator device.
These tests were done using the test stand, and moving the sensor from -45 to 45 degrees in 5 degree increments in each the roll and pitch direction, and from -80 to 80 degrees in 5 degree increments for the yaw direction. There are 5 tests for each direction to prove that the device and code are precise, and the results are reproducible.
- Test P1-P5: Precision of Pitch Direction
- Test P6-P10: Precision of Roll Direction
- Test P11-P15: Precision of Yaw Direction
- Knee Code Precision Testing
- Right Knee Test Results
These tests was done using the test rig. One sensor was placed on the table, the other on the test rig. The sensor on the test rig was started at 90 degrees (0 degrees of flexion) and then moved in 5 degree increments to about 64 degrees and then to about -55 degrees again by 5 degree increments. It can be seen from the graph that this is an accurate device within our customer's needs.
- Left Knee Test Results
This test was done using the test rig. One sensor was placed on the table, the other on the test rig. The sensor on the test rig was started at 90 degrees (0 degrees of flexion) and then moved in 5 degree increments to about 55 degrees and then to about -64 degrees again by 5 degree increments. It can be seen from the graph that this is an accurate device within our customer's needs.
- Test Rig Troubleshooting Results
These tests were done to troubleshoot both the test rig as well as the magnetometer in the Razor IMU device. Various ferrous materials were placed near the sensor to see if the sensor was effected. The base of the test rig was found to be a problem, as well as some ferrous screws used in the test rig. The sensor was also tested without a computer near it to test the effect that the computer had on the sensor. It was also placed on a piece of wood so that it was not near any interference. The magnetometer was then taken out of the code, and was not used which proved to be problematic in correcting for gyroscope drift. The final code includes the magnetometer.
This test was done by using the test rig. The sensor was moved in the yaw direction from 0 degrees to about 75 degrees and back to zero in 10 degree increments. The first half of the graph was done by having no ferrous base over the sensor, and the second half had the base held above the sensor while moving the sensor from 0 to 75 degrees once more. It can be seen from the graph that even with the new code there is some interference with ferrous materials. Although there is still interference, there is much less than with the previous code.
Ferrous objects had an effect on the accelerometers at a distance of 7.5 cm, but to be safe, we recommend not putting any ferrous objects within 15 cm (approx. half a foot) of the sensor system.
- Attachment and Enclosure Test Results
These tests were done on the actual enclosure and attachment method for the sensor. The attachment method proved to meet the customer's needs.
- Test E-1: Sanitation Test 1
- Test E-2: Sanitation Test 2
- Test E-3: Wearing Units Test
- Test E-4: Displacement Test
- Test E-5: Setup and Removal Test
- Test E-6: Weight of Enclosure Test
- Test E-7: Normal Force Test
- Test E-8: Dimensional Test