Thomas Tille

A High-Precision NDIR

A new high-precision spectroscopic gas sensor measuring carbon dioxide (CO2) for harsh environmental conditions of automotive applications is presented. The carbon dioxide concentration is the primary parameter for sensing in cabin air quality, as well as an important safety parameter when R744 (carbon dioxide) is used as the refrigerant in the air conditioning system. The automotive environment challenges the potential sensor principles because of the wide temperature range from -40degC to +85degC, the atmospheric pressure from 700 to 1050 mbar, and relative humidity from 0% to 95%. The presented sensor system is based on the nondispersive infrared principle with new features for reaching high precision criteria and for enhancing long-term stability. A second IR source is used for internal recalibration of the primary IR source, redundancy purposes, and software plausibility checks. The CO2 sensor system achieves an accuracy of better than plusmn5.5% over the whole temperature, pressure, and humidity ranges, with a resolution below 15 ppm and a response time shorter than 5 s. The operating time of the sensor system is more than 6000 h over a corresponding lifetime of more than 15 years. Experimental results show outstanding results for the intended automotive applications

\hbox{CO}_{2}

An area-efficient high-linearity MOSFET-only /spl Sigma//spl Delta/ modulator using depletion-mode MOS-capacitors in combined series and parallel compensation technique is presented. The new approach joins the advantages of the series and parallel compensation of depletion-mode MOS-capacitors, achieving an optimum of linearity and area efficiency. The 2/sup nd/-order fully-differential MOSFET-Only /spl Sigma//spl Delta/ modulator was implemented in a standard 0.25 /spl mu/m n-well digital CMOS process without extra layers for capacitors. The circuit operates at 1.8 V supply voltage, consumes 1 mW and achieves a SNR of 77 dB and a SNDR of 71 dB at a signal bandwidth of 8 kHz. The occupied core area is 0.06 mm/sup 2/.

Gas Sensor for Automotive Applications

Increased requirements regarding ergonomic comfort, limited space, weight reduction, and electronic automation of functions and safety features are on the rise for future automotive gear levers. At the same time, current mechanical gear levers have restrictions to achieve this. In this paper, we present a monostable, miniaturized mechatronic gear lever to fulfill these requirements for automotive applications. This solution describes a gear lever for positioning in the center console of a car to achieve optimal ergonomics for dynamic driving, which enables both automatic and manual gear switching. In this paper, we describe the sensor and actuator concept, safety concept, recommended shift pattern, mechanical design, and the electronic integration of this shift-by-wire system in a typical automotive bus communication network. The main contribution of this paper is a successful system design and the integration of a mechatronic system in new applications for optimizing the human-machine interface inside road vehicles.

A low-voltage MOSFET-only /spl Sigma//spl Delta/ modulator for speech band applications using depletion-mode MOS-capacitors in combined series and parallel compensation

Touch surfaces with no surface deformations delineating the individual function fields open up new design possibilities in the car interior. However, a haptic feedback signal similar to a mechanical button appears to be necessary for orientation and input acknowledgment. This has been put into practice in a new product by Continental, using active haptics in the form of an electromechanical concept. This article describes the review of this new products added value, and refutes potential disadvantages regarding its fitness for use compared with traditional solutions. The subjective perception of the active haptic feedback signal is also described. Three different empirical investigations, each with 20 test subjects, were carried out. Our results show that there is significant added value regarding the attractiveness of the new product. The absence of any shortcomings regarding its fitness for use compared with traditional solutions could not be proved conclusively. Nevertheless, interesting connections between the subjective perception of the haptic feedback signal and its intensity were observed.

Design of Highly Integrated Mechatronic Gear Selector Levers for Automotive Shift-by-Wire Systems

In the automotive industry, control panels and décor elements are designed as separate components which are geometrically and discretely combined. This considerably limits the technical variations of the design and the compactness of the construction. In this paper, the fusion of the control panel and the decorative surface to create a functional 3-D surface is presented. The approach is based on the integration of a touch sensor-based control and sensor module into a free-form decorative surface. For this purpose, an automotive-suitable touch sensor foil is used, made by silver paste screen printing technology. This highly sensitive touch sensor, which immediately reacts to the users touch by a visible feedback, creates an impression of excellent quality. The integration of this sensor module into the decorative surface combined with display elements is done by an innovative connection concept. Herewith, the limits of the decorative surface are compensated for and the touch sensor performances, as well as the transmittance properties, are reproducible and robust. The sensor module has a local interconnect network-bus interface and meets the automotive requirements.

Advantages of Active Haptics on Touch Surfaces

In Automobilen werden Bedienfelder und Dekorelemente bisher als separate Komponenten realisiert. Diese Modularitat beeintrachtigt die Kompaktheit und das Design der Interieur-Gestaltung. Durch das Verschmelzen von Bedienelementen mit Dekoroberflachen kann dieser Nachteil aufgehoben werden. In diesem Beitrag wird ein innovatives Touch-Sensor-basiertes Anzeige- und Bediensystem vorgestellt, das in eine 3D-Dekoroberflache integriert ist. Dadurch werden Human-Machine-Interface (HMI)- An wen dungen in freigestaltbaren Dekorflachen im Automobil ermoglicht.

3-D Surface-Integrated Touch-Sensor System for Automotive HMI Applications

This work is an analytical description of a phenomenon known as electron emission from ferroelectrics. The production of free electrons from the surface of ferroelectrics with a metal lattice structure will be explained. An analytical field calculation shows that with a given structure the apparent surface charges of the ferroelectrics produce an electric field, which causes an electron emission from the metal lattice because of the tunnel effect. The emission process is described on the basis of the Fowler-Nordheim formula. After the polarization change of the ferroelectrics, free electrons are produced as a result of the Coulomb interaction. In theory this work analyzes the question of producing high density electron currents by means of ferroelectric materials. The calculated values are compared to empirically found data.