Abstract
The automotive suspension plays a crucial role in vehicle safety and driving comfort. One of the most important components in vehicle suspensions is the damper (or shock absorber). Because there is no precise method to perform shock absorber test within the vehicle, an embedded autonomous system, powered by the energy harvested from the shock absorber itself, capable of monitoring shock absorber parameters and transmitting these values throughout a wireless interface to the vehicle central diagnostic unit, is presented. Such a device will permit the shock absorber condition assessment under vehicle operation, which to our best knowledge is considered a breakthrough in vehicle safety. © 2008 IEEE.

Abstract
Vehicles rely on the efficiency of dampers to dissipate energy from the motion of vehicle body and wheels, maintaining the vehicle more stable, and improving the contact between tires and the road surface. To achieve an effective monitoring of dampers (or shock absorbers), two different methodologies, capable of assessing, under vehicle normal operation, the condition of the automotive dampers are presented. The proposed methodologies are based in acceleration, temperature and pressure sensing to determine the shock absorber condition, and are therefore suitable for future implementation in low cost fabrication technologies. The results shown that it is possible to have an effective monitoring device, installed in the damper body, capable of continuously determining shock absorber status, and therefore enabling real time diagnosis. Such a diagnosis system can reduce the number of vehicles riding with defective suspension systems and increase the overall vehicle safety.

Abstract
A silicon soil moisture sensor, based in the dual-probe heat-pulse (DPHP) method, was modeled, simulated and tested for achieving, with low-cost, accurate and reliable measurements. This method is based on the application of a heat pulse during a fixed interval of time. The maximum rise in temperature (DeltaT(M)) is monitored by the measurement probe, placed at a certain distance of the heater source. A low-cost high-performance and small temperature sensor (a dynamic V-pTAT generator) was designed and fabricated to be placed into the probe which have 0.912 mm inner diameter and 20 mm long. If one considers the range of water contents, ratio of water mass to dry soil mass, in a typical agricultural soil (0.05-0.35 m(3) M-3), the average sensitivity of the dual probe is about 1.95 degreesC per unit change (m(3) M-3) in water content for q = 400 Jm(-1).

Abstract
This paper describes a wireless RF CMOS interface for soil moisture measurements. The interface basically comprises a Delta-Sigma (DeltaSigma) modulator for acquiring an external sensor signal, and a RF section where data is transmitted to a local processing unit. The DeltaSigma modulator is a single-bit, second-order modulator and it is implemented using switched-capacitors techniques in a fully-differential topology. With a sampling frequency of 423.75 kHz and an oversampling ratio (OSR) of 256, the modulator achieves a dynamic range of 98.7 dB (16.1 bit). The output of the modulator is applied to a counter, as a first-order decimation filter, and the result is stored. Prior to transmission, data is encoded as a pulse width modulated signal and assembled in a frame containing preamble and checksum control fields. This frame is then transmitted through a power amplifier operating at 433.92 MHz in class-E mode. To evaluate the DeltaSigma modulator performance, the bitstream was acquired and transferred to a personal computer to perform digital filtering and decimation using MATLAB. The soil moisture sensor is based on dual-probe heat-pulse (DPHP) method and is implemented by using an integrated temperature sensor and a heater. After applying a heat-pulse for a fixed period of time, the temperature rise, that is a function of soil moisture, generates a differential voltage that is amplified and applied to the mixed-signal interface input. The described interface can also be used with other kinds of environmental sensors in a wireless sensors network. The CMOS mixed-signal interface has been implemented in a single-chip using a standard CMOS 0.7 mum process (AMI C07M-A, n-well, 2 metals and 1 poly).

Abstract
This paper presents a piezoresistive pressure sensor with a measurement span of 1MPa and capable to withstand peak pressures around 10MPa. The sensor design, based on a square membrane, was optimized for enhanced sensitivity, high linearity and low sensitivity variations between fabricated samples. Being the asymmetry of the mechanical stress peaks, the ratio between the membrane area and its thickness, and the tolerances of the bulk micromachining process considered for the optimal positioning of the piezoresistive sensing elements. Practical results show a mean sensitivity of 30.9mV/V/MPa with a standard deviation of 0.65mV/V/MPa and a linearity error of 0.15% of the scale span. (C) 2012 Elsevier Ltd....Selection and/or peer-review under responsibility of the Symposium Cracoviense Sp. z.o.o.

Abstract
This article presents the characterization of a shock absorber embedded sensor (SAES) for real-time monitoring of the condition of vehicle shock absorbers in everyday use. A prototype system was built using a custom designed monolithic silicon combined accelerometer, pressure and temperature sensors. The characterization of the SAES was performed and the obtained results meet and even outperform the specification requirements. The SAES was installed in a shock absorber, with adjustable dampling properties, and submitted to road tests. Results show that the condition of a shock absorber can be effectively assessed with the presented SAES. Ensuring that shock absorbers are replaced before reach unacceptable condition, this system will increase onboard comfort and vehicle safety. (C) 2010 Published by Elsevier Ltd.