A ‘Giving way’ captured during walking by gyroscopes and plantar force sensors

The car weighting test system provides a good method to improve the comfort felt in car by passengers. It uses force sensors to measure the car load based on a optics-mechanical system that measure the displacement of an steel part which is proportional of the applied weight force.

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Nondestructive Detection of a Crack in a Triangular Cantilever Beam Based on Frequency Measurement

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.2285 ◽

2007 ◽

Vol 353-358 ◽

pp. 2285-2288

Author(s):

Fei Wang ◽

Xue Zeng Zhao

Keyword(s):

Cantilever Beam ◽

Natural Frequencies ◽

Frequency Measurement ◽

Crack Size ◽

Force Sensors ◽

Rotational Spring ◽

Cantilever Deflection ◽

Crack Location ◽

Small Force ◽

Point Of Intersection

Triangular cantilevers are usually used as small force sensors in the transverse direction. Analyzing the effect of a crack on transverse vibration of a triangular cantilever will be of value to users and designers of cantilever deflection force sensors. We present a method for prediction of location and size of a crack in a triangular cantilever beam based on measurement of the natural frequencies in this paper. The crack is modeled as a rotational spring. The beam is treated as two triangular beams connected by a rotational spring at the crack location. Formulae for representing the relation between natural frequencies and the crack details are presented. To detect crack details from experiment results, the plots of the crack stiffness versus its location for any three natural modes can be obtained through the relation equation, and the point of intersection of the three curves gives the crack location. The crack size is then calculated using the relation between its stiffness and size. An example to demonstrate the validity and accuracy of the method is presented.

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Estimation of Sideslip and Roll Angles of Electric Vehicles Using Lateral Tire Force Sensors Through RLS and Kalman Filter Approaches

IEEE Transactions on Industrial Electronics ◽

10.1109/tie.2012.2188874 ◽

2013 ◽

Vol 60 (3) ◽

pp. 988-1000 ◽

Cited By ~ 132

Author(s):

Kanghyun Nam ◽

Sehoon Oh ◽

Hiroshi Fujimoto ◽

Yoichi Hori

Keyword(s):

Kalman Filter ◽

Electric Vehicles ◽

Force Sensors ◽

Tire Force

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Research on PVDF Micro-Force Sensor

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.599-601.1135 ◽

2014 ◽

Vol 599-601 ◽

pp. 1135-1138

Author(s):

Chao Zhe Ma ◽

Jin Song Du ◽

Yi Yang Liu

Keyword(s):

Power Dissipation ◽

Polyvinylidene Fluoride ◽

High Sensitivity ◽

Force Sensor ◽

Calibration Method ◽

Pvdf Film ◽

Force Sensors ◽

Low Power Dissipation ◽

Micro Force Sensor ◽

Processing Circuit

At present, sub-micro-Newton (sub-μN) micro-force in micro-assembly and micro-manipulation is not able to be measured reliably. The piezoelectric micro-force sensors offer a lot of advantages for MEMS applications such as low power dissipation, high sensitivity, and easily integrated with piezoelectric micro-actuators. In spite of many advantages above, the research efforts are relatively limited compared to piezoresistive micro-force sensors. In this paper, Sensitive component is polyvinylidene fluoride (PVDF) and the research object is micro-force sensor based on PVDF film. Moreover, the model of micro-force and sensor’s output voltage is built up, signal processing circuit is designed, and a novel calibration method of micro-force sensor is designed to reliably measure force in the range of sub-μN. The experimental results show the PVDF sensor is designed in this paper with sub-μN resolution.

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Model Calibration for a Rigid Hexapod-Based End-Effector with Integrated Force Sensors

Sensors ◽

10.3390/s21103537 ◽

2021 ◽

Vol 21 (10) ◽

pp. 3537

Author(s):

Christian Friedrich ◽

Steffen Ihlenfeldt

Keyword(s):

Parameter Identification ◽

Degrees Of Freedom ◽

Force Measurement ◽

Experimental Studies ◽

Measurement Model ◽

Calibration Procedure ◽

Force Sensors ◽

End Effector ◽

Measurement Models ◽

Fast Procedure

Integrated single-axis force sensors allow an accurate and cost-efficient force measurement in 6 degrees of freedom for hexapod structures and kinematics. Depending on the sensor placement, the measurement is affected by internal forces that need to be compensated for by a measurement model. Since the parameters of the model can change during machine usage, a fast and easy calibration procedure is requested. This work studies parameter identification procedures for force measurement models on the example of a rigid hexapod-based end-effector. First, measurement and identification models are presented and parameter sensitivities are analysed. Next, two excitation strategies are applied and discussed: identification from quasi-static poses and identification from accelerated continuous trajectories. Both poses and trajectories are optimized by different criteria and evaluated in comparison. Finally, the procedures are validated by experimental studies with reference payloads. In conclusion, both strategies allow accurate parameter identification within a fast procedure in an operational machine state.

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Direct ink write multi-material printing of PDMS-BTO composites with MWCNT electrodes for flexible force sensors

Flexible and Printed Electronics ◽

10.1088/2058-8585/ac442e ◽

2021 ◽

Author(s):

Anabel Renteria ◽

Victor Hugo Balcorta ◽

Cory Marquez ◽

Aaron Arturo Rodriguez ◽

Ivan Renteria-Marquez ◽

...

Keyword(s):

Piezoelectric Properties ◽

Fixed Ratio ◽

Force Sensors ◽

Piezoelectric Composites ◽

Mixing Ratios ◽

Multi Walled Carbon Nanotubes ◽

One Step ◽

Corona Poling ◽

Material Printing ◽

Walled Carbon Nanotubes

Abstract With recent advances of additive manufacturing (AM) technology, direct ink write (DIW) printing has allowed to incorporate multi-material printing of various materials with freedom of design and complex geometric shapes to complete functional sensors in a one-step fabrication. This paper introduces the use of DIW 3D printing of polydimethylsiloxane (PDMS) with barium titanate (BTO) filler as stretchable composites with tunable piezoelectric properties that can be used for force sensors applications. To improve the bonding between stretchable piezoelectric composites and electrodes, multi-walled carbon nanotubes (MWCNT) was included in the fabrication of electrodes at a fixed ratio of 11 wt. %. The alignment of the BTO dipoles was achieved through corona poling method, which applies an electric charge on the surface layer of the functional material, aligning the dipoles in the desired direction and thus gaining the piezoelectricity. Different BTO mixing ratios (10-50 wt. %) were evaluated in order to obtain tunable piezoelectric properties and compare the sensitivity with respect their elastic properties. Tensile testing and piezoelectric testing were carried out to characterize mechanical and piezoelectric properties. Results showed that fabricated PDMS with 50 wt. % BTO gave the highest piezoelectric coefficient (d33) of 11.5 pC/N and with an output voltage of 385 mV under compression loading of >200 lbF. This demonstrates feasibility of using multi-material DIW printing to fabricate piezoelectric force sensors with integrated electrodes in one-step without compromising the flexibility of the material.

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