Pressure Sensitive Floor Sensing

Pressure Sensitive Floor - FSR evaluation back to pressure sensitive floor home
We explored several sensors and approaches to make the device flexible, reliable and easy to use.We explored several sensors and approaches to make the device flexible, reliable and easy to use. FlexiForce® Product Group: FlexiForce®, a division of Tekscan, manufactures the ELF™ (Economical Load & Force) system, Multi-Handle ELF™ system, and FlexiForce® sensors. ZOFLEX® ZL60 Sensors: We also tested a number of pressure sensitive rubber materials from Xilor inc. in an attempt to design a sensor element that is custom tailored for this application. While there is promise to use this material for future development work, we found out that complex mechanical packaging is needed to realize a robust sensor element. Interlink FSR® Sensors: Though costly, the Interlink 400 FSR was finally chosen for its small size (0.012” thickness), dynamic range, rugged construction and relatively lower overall system cost. Its force sensitivity range, 30gm ~ 10kg, is sufficient for collecting pressure data without a need for additional amplification circuitry in a dance environment. http://www.fsrlink.com/ Tekscan mat sensors #5315: The 5315 sensor from Tekscan is currently being used in the pressure sensitive floor as it utilizes similar FSR technology utilizing resistive film. It is, however, structured in a matrix format packing 2016 elements in approximately 323 sq. in. area. Other Sensors: https://www.rfmicrolink.com/zoflex.html Basic Sensors (PS3): Individual, single key PST sensors, usually supplied with a square, rectangular or circular active area and a tail which terminates with a connector. Capacitive sensor from Serena: The data from the sensor(s) is converted by the data acquisition software into real-time visual information, and also into a format that is recognized by Microsoft Excel©. This brings the full power of the spreadsheet software into action for analyzing and graphing force data collected with the sensor or sensors. Capacitive sensors are suitable for platform type weight measurement systems where a rigid plate is supported by these sensors at its four corners. Sensor Testing: The test setup employed to characterize sensors is shown in the figure below. It consists of a load cell wired to digital readout for measuring force in the Z-direction, a digital ohmmeter for measuring resistance, and a micrometer for measuring displacement in the Z direction. Each type of sensor was tested from a load range of 0-5kg in continuously variable increments. Data from the load cell reading and ohmmeter reading were then plotted on an X-Y log grid and compared. The result for Interlink400 FSR is shown in the plot below: The Bulk FSR materials lacked repeatability and suffered from high hysteresis. Also the customization and installation of these sensors was found to be labour-intensive. The resistance vs force graph shown below is for the model 5315 mat sensel rated at 30 psi. Data was generated by applying force on the sensors through a 2"x2" wooden block. Applied force is distributed over 25 sensels in this arrangement. Similar result was obtained for a single sensel when pressure was applied through a 0.1" puck. A movie clip testing the dynamic range of the mat can be viewed here. The corresponding test setup is shown below.

Pressure Sensitive Floor - FSR evaluation

We explored several sensors and approaches to make the device flexible, reliable and easy to use.We explored several sensors and approaches to make the device flexible, reliable and easy to use.

FlexiForce® Product Group:

FlexiForce®, a division of Tekscan, manufactures the ELF™ (Economical Load & Force) system, Multi-Handle ELF™ system, and FlexiForce® sensors.

ZOFLEX® ZL60 Sensors:

We also tested a number of pressure sensitive rubber materials from Xilor inc. in an attempt to design a sensor element that is custom tailored for this application. While there is promise to use this material for future development work, we found out that complex mechanical packaging is needed to realize a robust sensor element.

Interlink FSR® Sensors:

Though costly, the Interlink 400 FSR was finally chosen for its small size (0.012” thickness), dynamic range, rugged construction and relatively lower overall system cost. Its force sensitivity range, 30gm ~ 10kg, is sufficient for collecting pressure data without a need for additional amplification circuitry in a dance environment.

http://www.fsrlink.com/

Tekscan mat sensors #5315:

The 5315 sensor from Tekscan is currently being used in the pressure sensitive floor as it utilizes similar FSR technology utilizing resistive film. It is, however, structured in a matrix format packing 2016 elements in approximately 323 sq. in. area.

Other Sensors:

https://www.rfmicrolink.com/zoflex.html

Basic Sensors (PS3): Individual, single key PST sensors, usually supplied with a square, rectangular or circular active area and a tail which terminates with a connector.

Capacitive sensor from Serena: The data from the sensor(s) is converted by the data acquisition software into real-time visual information, and also into a format that is recognized by Microsoft Excel©. This brings the full power of the spreadsheet software into action for analyzing and graphing force data collected with the sensor or sensors.

Capacitive sensors are suitable for platform type weight measurement systems where a rigid plate is supported by these sensors at its four corners.

Sensor Testing:

The test setup employed to characterize sensors is shown in the figure below. It consists of a load cell wired to digital readout for measuring force in the Z-direction, a digital ohmmeter for measuring resistance, and a micrometer for measuring displacement in the Z direction. Each type of sensor was tested from a load range of 0-5kg in continuously variable increments. Data from the load cell reading and ohmmeter reading were then plotted on an X-Y log grid and compared.

The result for Interlink400 FSR is shown in the plot below:

The Bulk FSR materials lacked repeatability and suffered from high hysteresis. Also the customization and installation of these sensors was found to be labour-intensive.

The resistance vs force graph shown below is for the model 5315 mat sensel rated at 30 psi. Data was generated by applying force on the sensors through a 2"x2" wooden block. Applied force is distributed over 25 sensels in this arrangement. Similar result was obtained for a single sensel when pressure was applied through a 0.1" puck. A movie clip testing the dynamic range of the mat can be viewed here.

The corresponding test setup is shown below.