Tactile Occupant Detection Sensor for Automotive Airbag

Automotive airbags protect occupants from crash forces during severe vehicle collisions. They absorb energy and restrain the occupants by providing a soft cushion effect known as the restraint effect. Modern airbags offer partial restraint effect control by controlling the bag’s vent holes and providing multi-stage deployment. Full restraint effect control is still a challenge because the closed-loop restraint control system needs airbag–occupant contact and interaction feedback. In this work, we have developed novel single and matrix capacitive tactile sensors to measure the occupant’s contact data. They can be integrated with the airbag surface and folded to follow the dynamic airbag shape during the deployment. The sensors are tested under a low-velocity pendulum impact and benchmarked with high-speed test videos. The results reveal that the single sensor can successfully measure occupant–airbag contact time and estimate the area, while the contact position is additionally identified from the matrix sensor.

A simple laser beam characterization apparatus based on imaging

The development of an original low-cost hardware/software apparatus to optically control the laser beam and measure quality parameters by image analysis using a monochrome matrix sensor is described, along with experimental validation. Laser parameters, namely beam waist, divergence, Rayleigh range and M2, which are the most relevant in manufacturing operations (like optical measurement and laser processing), have been physically and mathematically characterized. Strategies for the apparatus size reduction are also presented, including the use of a prism to reduce by half the optical path, and a camera model to simulate the sensor resolution.

Carbon Nanotubes Reinforced Natural Rubber Composites

Several advanced methods have been introduced to disperse CNTs in the NR matrix. Various aspects highlighted in this chapter include the mixing processes such as melt mixing and latex mixing methods. As well as, formations of functional groups on the surfaces of CNT using silane coupling agents (i.e., ex-situ and in-situ functionalization). Moreover, hybrid CNT are beneficial to achieve better electrical conductivity of NR/CNT composites. These efforts are aimed to reduce the percolation threshold concentration in the NR composites for application as conducting composites based on electrically insulating rubber matrix. Sensor application is developed based on conducting NR composites. NR composites showed changing of resistivity during elongation termed as piezoresistivity. The most commonly used rubber matrices such as NR, ENR and IR are mixed with a combination of CNT and CB fillers as hybrid filler. The presence of linkages in the ENR composites results in the least loss of conductivity during external strain. It is found that the conductivity becomes stable after 3000 cycles. This is found to be similar to the NR-CNT/CB composite, while a few cycles are needed for IR-CNT/CB owing to the higher filler agglomeration and poor filler-rubber interactions. This is attributed to the polar chemical interactions between ENR and the functional groups on the surfaces of CNT/CB.

Evaluation of time response of GMS for soil suction measurement

The Granular Matrix Sensor (GMS) is an indirect method for soil suction measurement. Since GMS is comparatively inexpensive, robust and usually provide continuous soil suction data, it is a natural candidate for civil engineering practice. The sensor has been used mainly for irrigation purposes, and also for some civil engineering activities. Questions about its effectiveness and reliability are still posed, making studies about this topic desirable. This study presents a laboratory comparison between Watermark and an ordinary tensiometer during an equilibrium period and for a wetting procedure performed in a compacted sandy silt soil (residual soil of gneiss). The results yielded that GMS may provide tensiometer equivalent suction values in a context of no significant water content variation. However, it takes a longer time to obtain stabilized suction values. During the wetting procedure, GMS presented a delay of about 2 h in detecting water while tensiometer detection was almost instantaneous.

Motion Detection Using Tactile Sensors Based on Pressure-Sensitive Transistor Arrays

In recent years, to develop more spontaneous and instant interfaces between a system and users, technology has evolved toward designing efficient and simple gesture recognition (GR) techniques. As a tool for acquiring human motion, a tactile sensor system, which converts the human touch signal into a single datum and executes a command by translating a bundle of data into a text language or triggering a preset sequence as a haptic motion, has been developed. The tactile sensor aims to collect comprehensive data on various motions, from the touch of a fingertip to large body movements. The sensor devices have different characteristics that are important for target applications. Furthermore, devices can be fabricated using various principles, and include piezoelectric, capacitive, piezoresistive, and field-effect transistor types, depending on the parameters to be achieved. Here, we introduce tactile sensors consisting of field-effect transistors (FETs). GR requires a process involving the acquisition of a large amount of data in an array rather than a single sensor, suggesting the importance of fabricating a tactile sensor as an array. In this case, an FET-type pressure sensor can exploit the advantages of active-matrix sensor arrays that allow high-array uniformity, high spatial contrast, and facile integration with electrical circuitry. We envision that tactile sensors based on FETs will be beneficial for GR as well as future applications, and these sensors will provide substantial opportunities for next-generation motion sensing systems.

POTENTIALLY ACHIEVABLE LEVEL IMAGE DEFINITION IN VIDEO APPLICATIONS

The paper gives an estimate of the potentially achievable level of definition for light-to-light video transmission path, which can be considered as ideal, i.e. such that a decrease in definition in it occurs only due to the diffraction limitations of the camera lens and the finite dimensions of the transforming elements of the camera matrix sensor and of the reproducing display without additional image processing. Examples of MTF of end-to-end paths for SDTV, HDTV, UHDTV 4K and UNDTV 8K systems for the specified parameters of the lens and camera sensor, taking into account the distortions introduced by the reproducing display, are presented.