Abstract: An operating method for a fresh-air feed device for an internal combustion engine is configured for feeding fresh air from the environment surrounding the internal combustion engine into at least one combustion chamber of the internal combustion engine. A controllable throttle valve is configured for varying a through-flowable area of the fresh-air feed device and for at least partially shutting off the fresh-air feed device. The device has a compressor which is arranged upstream of the throttle valve in an intended through-flow direction from the environment into the combustion chamber, which is configured for conveying an air mass flow in the intended through-flow direction in the fresh-air feed device. A pre-compressor section of the device is arranged upstream of the compressor, an intermediate section is arranged downstream of the compressor device and upstream of the throttle valve, and a post-throttle section is arranged downstream of the throttle valve.

Abstract: A method for temperature compensation of a MEMS sensor. The method includes: in a balancing step, a temperature gradient is produced by a thermal element and a first and a second temperature are determined at a first and a second temperature measurement point, wherein a deflection of a movable structure produced by the temperature gradient is measured and a compensation value is ascertained dependent on the first and second temperature and the deflection; in a measurement step, a physical stimulus is measured by way of a deflection of the movable structure and a third and fourth temperature is determined at the first and second temperature measurement points; in a compensation step, a measured value of the physical stimulus is ascertained dependent on the measured deflection, the third and fourth temperature and the compensation value. A method is also provided including: a regulation step, and a measurement step.

Abstract: An inertial measurement unit includes: a sensor unit having an inertial sensor; and a first holding unit holding the sensor unit. The first holding unit includes: a first substrate; a second substrate; a plurality of spacers coupling the sensor unit and the first substrate; a first elastic member and a second elastic member provided on both sides of the first substrate via opening parts; a first fixing member penetrating, pressing and fixing the first substrate and the first elastic member to the second substrate; and a second fixing member penetrating, pressing and fixing the first substrate and the second elastic member to the second substrate.

Abstract: An inertial measurement unit (IMU) device includes a circuit board assembly including a rigid circuit board and a flexible circuit board, an IMU sensor disposed on the rigid circuit board, and a heat preservation system. The IMU sensor is electrically connected to an external element through the flexible circuit board to transmit at least one of a signal or power between the IMU sensor and the external element. The heat preservation system includes a heat source, a heat preservation body with a receiving space to accommodate the IMU sensor, and a heat conductive member configured to transfer heat from the heat source to the IMU sensor to maintain the IMU sensor at a preset temperature. The heat conductive member includes an electrically insulating and thermally conductive silicone.

Abstract: Aspects presented herein may enable an electronic device to determine gyroscope biases and calibrate a gyroscope without a magnetometer or without relying on data generated from a magnetometer. In one aspect, an apparatus estimates a set of gyroscopic biases for a plurality of temperatures or temperature ranges to create a mapping that maps the plurality of temperatures or temperature ranges to the set of gyroscopic biases. The apparatus monitors temperatures of a gyroscope via a gyroscope temperature sensor. The apparatus calibrates the gyroscope in response to the gyroscope changing from a first temperature to a second temperature based on the mapping or based on a predicted value derived from the mapping. In some aspects, the apparatus calculates a DR trajectory of the apparatus based at least in part on the calibrated gyroscope and the accelerometer without using a magnetometer or without using data generated from the magnetometer.

Abstract: An inertial measurement unit includes an angular velocity sensor and an acceleration sensor that output inertial information, a storage portion that stores a plurality of correction parameters related to a range of values of the inertial information, a parameter control portion that selects a selection correction parameter from the plurality of correction parameters, and a correction calculation portion that corrects the inertial information using the selection correction parameter.

Abstract: An inertial sensor includes a lower substrate and an upper substrate. The upper substrate includes a micro oscillator, electrodes and a pad, which are independent of each other. The micro oscillator includes a curved surface portion, a joint portion recessed inward from an apex of the curved surface portion and joined to a support portion of the lower substrate, a rim at an end of the curved surface portion and a conductive film covering the micro oscillator. The curved surface portion is in an aerial state. The rim is made of the same material as the electrodes, located on a virtual flat plane formed by the electrodes, and apart from and surrounded by the electrodes. A portion of the conductive film that covers the joint portion is electrically bonded to a lower metal film covering the support portion.

Abstract: A method for compensating for a temperature drift of an accelerometer for measuring the lateral tilt of a motorbike. When the vehicle is in the “bike upright” condition, and the temperature of the accelerometer is at least 30° C. above its reference temperature, a reading is taken of the acceleration values. These values are then processed in order to identify the coefficient of the slope of the straight line for correcting the offset of each axis of the accelerometer. A processing operation involves verifying the strict monotony of the coefficients in at least two successive readings and ensuring that the mean value thereof is included between determined limits. The mean coefficient that is finally obtained then can be used to correct the temperature of accelerations read over the entire operating range of the accelerometer. Thus, the computation of the tilt angle of the motorbike is more precise.

Abstract: Described herein are methods and systems for configuring a motion sensor assembly to compensate for a temperature gradient. First and second sensors of the same type are arranged as opposing pairs with respect to a first axis that may be defined by a temperature gradient caused by at least one thermal element. Combining the output measurements of the first sensor and the second sensor allows effects of the temperature gradient on sensor measurements of the first sensor and the second sensor to be compensated.

Abstract: An inertial measurement unit includes a sensor and a heat preservation system. The heat preservation system includes a heat preservation body and a heat source. The sensor is positioned on the heat preservation body. The heat source is configured to generate heat. The heat preservation body is configured to transfer the heat from the heat source to the sensor to maintain a preset temperature in a space surrounding the sensor.

Abstract: An inertial measurement unit includes: a sensor unit having at least one inertial sensor; a substrate where at least one of a processing unit performing processing based on detection information from the inertial sensor and a display unit performing a display based on the detection information is provided; and at least one fixing member removably fixing the sensor unit and the substrate together.

Abstract: An angular velocity sensor comprises: an insulative support layer (10); a substrate layer (8) formed of a silica-based material and comprising a planar ring structure (2) mounted to vibrate in-plane; and a plurality of conductive electrodes (14), each comprising a first set of moveable conductive electrode tracks (14a) formed on a surface of the planar ring and a second set of fixed conductive electrode tracks (14b) formed on a surface of the insulative support layer axially spaced from the surface of the planar ring. The first and second sets of conductive electrode tracks are interdigitated with a lateral spacing between them in a radial direction. Each moveable conductive electrode track has a radial offset from a median line between adjacent fixed conductive electrode tracks such that each moveable conductive electrode track has a different lateral spacing from two different adjacent fixed conductive electrode tracks in opposite radial directions.

Abstract: The disclosure relates to a microelectromechanical gyroscope which comprises first and second proof masses which form a first proof mass pair and third and fourth proof masses which form a second proof mass pair. The oscillation of the first and second proof mass pairs is synchronized by a synchronization element which comprises a ringlike body and torsion bars which extend along the x-axis from the ringlike body to the first, second, third and fourth proof masses.

Abstract: Various embodiments of the present technology may provide a method and apparatus for a processing circuit. The processing circuit may include an amplifier and other processing circuitry that operate together to process and/or adjust a gyro signal. The processing circuit may include an integration circuit configured to compute a first value and adjust the first value to a predetermined maximum value if the first value is greater than the predetermined maximum value. The processing circuit may also include a gain control circuit configured to compute a first coefficient based on the first value; select one of: the first coefficient and a second coefficient; and adjust a gain of the amplifier according to the selected coefficient.

Abstract: A magnetic circuit assembly for an accelerometer includes an excitation ring that includes a base portion defining oppositely facing first and second sides, a ring portion extending from the second side of the base portion to define a ring recess, a first metallic inlay recessed into the first side of the base portion in which the first metallic inlay includes a material different than that of the base portion, a second metallic inlay recessed into the second side of the base portion in which the second metallic inlay includes a material different than that of the base portion, and a magnet received within the ring recess and attached to the second metallic inlay.

Abstract: An image forming apparatus that forms an image on a sheet includes: a rotating body that forms the image; a motor that rotationally drives the rotating body; a current measurer that measures a motor current flowing through a current supply path including a winding of the motor at a measurement timing that is a timing after the motor is started; a torque acquisitor that acquires a torque value of the motor, based on a measured value of the motor current; and a corrector that performs correction to cancel a current change amount based on a characteristic change depending on a temperature state of the motor at the measurement timing, in acquisition of the torque value by the torque acquisitor.

Abstract: Systems and methods are provided for calibrating and regulating the temperature of a sensor. One or more temperature adjusting devices can be provided to regulate the temperature of the sensor. One or more of the temperature adjusting devices can be provided to perform a calibration to determine a relationship between sensor bias and sensor temperature. The one or more temperature adjusting devices can be built into the sensor.

Abstract: An angular velocity sensor including a vibration body having a sensor electrode, a driving electrode, and a monitor electrode. The monitor electrode generates a signal according to vibration of the vibration body. The sensor circuit outputs a signal representing an angular velocity applied to the vibration body. The amplitude determination circuit measures amplitude of vibration of the vibration body. A PLL circuit includes a constant voltage source for generating a constant voltage, a timing switching unit for outputting a voltage by switching selectively between the constant voltage and a voltage corresponding to the monitor signal, and a voltage-controlled oscillator for outputting an oscillation signal having a frequency corresponding to the voltage output from the timing switching unit. When the amplitude measured is smaller than a predetermined value, the timing switching unit outputs the constant voltage output from the constant voltage source and outputs a start-up mode signal.

Abstract: An inertial force sensor includes: an acceleration detection element; a temperature sensor that detects an ambient temperature of the acceleration detection element; a bridge circuit that processes an output signal from the acceleration detection element; an AD converter that converts an analog signal output from the bridge circuit into a digital signal, and outputs the digital signal; a calculation circuit that performs calculation on the output signal from the AD converter; and a storage that stores correction data for correcting a variation in the output signal from the AD converter due to a temperature change. The correction data are coefficients of a formula expressed by a calibration curve that is a quadratic or higher-degree curve, and the storage stores, as the correction data, the coefficients of the calibration curve of each of a plurality of patterns that differ between a predetermined temperature or more and less than the predetermined temperature.

Abstract: In one embodiment, a sensor includes a rigid wafer outer body. A first cavity is located within the rigid wafer outer body, and a first vibration isolating spring is supported by the rigid wafer outer body and extends into the first cavity. A second vibration isolating spring is supported by the rigid wafer outer body and extends into the first cavity, and a first sensor packaging is supported by the first vibration isolating spring and the second vibration isolating spring within the first cavity.

Abstract: A physical quantity detection circuit includes: a synchronous detection circuit that performs a synchronous detection process on a detection target signal based on a detection signal, the detection target signal including a physical quantity detection signal and a leakage signal from a physical quantity detection element, the physical quantity detection element vibrating based on a drive signal to generate the physical quantity detection signal corresponding to a magnitude of a physical quantity, and the leakage signal of vibrations based on the drive signal; and a phase shift circuit that switches a phase difference between the detection signal and the detection target signal, between a first phase difference and a second phase difference that differs from the first phase difference, so that at least part of the leakage signal is output through the synchronous detection process.

Abstract: A resonant sensor includes a proof body having a first and a second interface that can each come into contact with an external mechanical structure; two sensitive zones arranged between these two interfaces; a sensitive zone formed by a plate embedded in a frame secured mechanically to the interfaces, the plate able to resonate under the effect of local mechanical excitations produced at particular points by excitation transducers bearing the plate at several resonant frequencies, sensors picking up the resonant signals produced at the particular points, measurement means measuring the resonant frequency shifts of signals which are linear combinations of the resonant signals picked up, the shifts being a function of mechanical stresses induced by the forces and transmitted to the plate by the frame, the components of the torque of forces being determined from the resonant frequency shifts measured on the plates of the sensitive zones.

Abstract: A semiconductor device according to the present invention includes plural temperature sensors; a switching circuit that switches between detection signals from the temperature sensors at a predetermined frequency; an ADC that receives the output of the switching circuit and outputs a converted signal; a correction information extracting circuit that generates a temperature mean value; and an abnormality information extracting circuit that generates a temperature difference value.

Abstract: The present invention provides a magnetic force sensor that can precisely detect and correct variations in a magnetic field generated by a magnetic flux generating source. Therefore, a displacement magneto-electric transducer, which detects a change in the magnetic field caused by an external force, and a fixed magneto-electric transducer, where the change in the magnetic field caused by the external force does not occur, are provided to face end sides of magnetic poles of the magnetic flux generating source. The fixed magneto-electric transducer detects a variation of the magnetic field caused by, for example, changes with time and environmental variations such as a temperature rise in the interior of the sensor. On the basis of a detection amount thereof, an operational section performs a correction operation, so that a sensitivity coefficient or an offset of the displacement magneto-electric transducer is corrected.

Abstract: A MEMS apparatus comprising composite vibrating unit and the manufacturing method thereof are disclosed. The vibrating unit includes a stiffness element on which a first material is disposed. A second material being a conductive material is disposed on the first material and is extended to the stiffness element to remove electric charge on first material. When a temperature is changed, a variation direction of a Young's modulus of the first material is opposite to a variation direction of a Young's modulus of the stiffness element. The unique attributes above allow vibrating unit of the MEMS apparatus such as resonator and gyroscope to have stable resonance frequency against the change of temperature.

Abstract: A precision gyroscope includes a gyroscope, means for receiving an external clock reference, and circuitry coupled to the means for receiving the external clock reference and adapted for stabilizing a temperature and a frequency of the gyroscope.

Abstract: An apparatus for detecting rotational speed includes a lead wire having a signal line covered with a sheath layer and a rotational speed detector connected to the lead wire and outputting an electrical signal corresponding to an object rotation. The apparatus for detecting rotational speed further includes a housing having the rotational speed detector inside and a resin stay integrally holding the housing and the lead wire. The resin stay includes at least one hole formed thereon.

Abstract: An optical sensor having one or more sensing interference elements is disclosed. A first detector function generates a coarse optical path difference signal for example using a discrete Fourier transform of a detected interference spectrum, and a second detector function generates a refined optical path difference signal using the coarse optical path difference signal and for example a cross correlation of the interference spectrum with one or more sets of periodic transfer functions.

Abstract: A micro-electromechanical device includes a semiconductor substrate, in which a first microstructure and a second microstructure of reference are integrated. The first microstructure and the second microstructure are arranged in the substrate so as to undergo equal strains as a result of thermal expansions of the substrate. Furthermore, the first microstructure is provided with movable parts and fixed parts with respect to the substrate, while the second microstructure has a shape that is substantially symmetrical to the first microstructure but is fixed with respect to the substrate. By subtracting the changes in electrical characteristics of the second microstructure from those of the first, variations in electrical characteristics of the first microstructure caused by changes in thermal expansion or contraction can be compensated for.

Abstract: An angular velocity detection apparatus includes a vibrator that generates a signal that includes an angular velocity component and a vibration leakage component, a driver section that generates the drive signal, and supplies the drive signal to the vibrator, an angular velocity signal generation section that extracts the angular velocity component from the signal generated by the vibrator, and generates an angular velocity signal corresponding to the magnitude of the angular velocity component, a vibration leakage signal generation section that extracts the vibration leakage component from the signal generated by the vibrator, and generates a vibration leakage signal corresponding to the magnitude of the vibration leakage component, and an adder-subtractor section that adds the vibration leakage signal to the angular velocity signal, or subtracts the vibration leakage signal from the angular velocity signal, in a given ratio to correct temperature characteristics of the angular velocity signal.

Abstract: An angular velocity detection circuit is connected to a resonator for making excited vibration on the basis of a drive signal and detects an angular velocity. The angular velocity detection circuit includes: a self-vibration component extraction unit that receives, from the resonator, a detection signal including an angular velocity component based on a Coriolis force and a self-vibration component based on the excited vibration and extracts the self-vibration component from the detection signal; a direct-current conversion unit including an integration unit that integrates an output signal of the self-vibration component extraction unit; and a temperature characteristic compensation unit that compensates for a variation due to a temperature in an output signal of the direct-current conversion unit.

Abstract: An angular velocity detection circuit is connected to a resonator for making excited vibration on the basis of a drive signal and detects an angular velocity. The angular velocity detection circuit includes: a self-vibration component extraction unit that receives, from the resonator, a detection signal including an angular velocity component based on a Coriolis force and a self-vibration component based on the excited vibration of the resonator and extracts the self-vibration component from the detection signal; a direct-current conversion unit including an integration unit that integrates an output signal of the self-vibration component extraction unit; and an offset addition unit that adds an offset value to an output signal of the direct-current conversion unit.

Abstract: A personal mobile device housing contains a display screen, a wireless telephony communications transceiver, and a battery charger interface. A temperature sensor and a gyro sensor whose zero turn rate output contains an offset are also included. A lookup table has gyro zero turn rate offset correction values associated with different temperature values. A programmed processor accesses the lookup table to correct the output of the gyro sensor for zero turn rate offset. It is automatically determined, during in-the-field use, when the device is in a motionless state, and the output of the temperature and gyro sensors are read. The read gyro output is written to the lookup table as part of a pair of associated temperature and zero turn rate offset correction values. Other embodiments are also described and claimed.

Abstract: A thermally controlled gas bearing supported inertial measurement unit (IMU) system is provided. The system comprises a sensor assembly enclosing one or more sensors and a plurality of heating elements, wherein each of the plurality of heating elements is proximal to the sensor assembly. The system also comprises a plurality of temperature sensors configured to determine a temperature of a region of the sensor assembly and a control unit configured to adjust a temperature of at least one of the plurality of heating elements based on feedback from the at least one temperature sensor.

Abstract: A device is described for use in performing an inground operation. An accelerometer is supported by the device for generating accelerometer readings that characterize the inground operation subject to a native temperature drift of the accelerometer. A set of compensation data is developed and stored for use in compensating for the native temperature drift. The compensation data is applied to the accelerometer readings to produce compensated accelerometer readings that externally compensate for the native temperature drift to yield an enhanced thermal performance which is improved as compared to a native thermal performance of the accelerometer. A seven position calibration method for a triaxial accelerometer is described. An air module is described which isolates the accelerometer of the device at least from a potting compound that at least fills otherwise unoccupied volumes of the device interior.

Abstract: A smart sensor circuit board comprises an interface to a wireless smart sensor board platform, a multi-axis accelerometer having a sensitivity that can measure ambient structural vibrations resulting from non-catastrophic routine environmental factors, an analog to digital converter (ADC) for converting signals from the multi-axis accelerometer having a plurality of individual channels including oversampling, filtering, and decimation, and each channel being individually programmable for gain, anti-aliasing, cut-off frequency, sampling, and frequency providing data to the interface, and a low noise and high sensitivity amplifier having the plurality of individual channels to receive signals from the multi-axis accelerometer.

Abstract: A precision gyroscope includes a semiconductor substrate, a gyroscope integrated on the substrate, and a quartz resonator clock integrated on the substrate. In another embodiment the substrate is a quartz substrate.

Abstract: An angular velocity detection circuit is connected to a resonator for making excited vibration on the basis of a drive signal and detects an angular velocity. The angular velocity detection circuit includes: a self-vibration component extraction unit that receives, from the resonator, a detection signal including an angular velocity component based on a Coriolis force and a self-vibration component based on the excited vibration and extracts the self-vibration component from the detection signal; a direct-current conversion unit including an integration unit that integrates an output signal of the self-vibration component extraction unit; and a temperature characteristic compensation unit that compensates for a variation due to a temperature in an output signal of the direct-current conversion unit.

Abstract: A micromachined thermal and mechanical isolator for MEMS die that may include two layers, a first layer with an active temperature regulator comprising a built-in heater and temperature sensor and a second layer having mechanical isolation beams supporting the die. The isolator may be inserted between a MEMS die of a disc resonator gyroscope (DRG) chip and the leadless chip carrier (LCC) package to isolate the die from stress and temperature gradients. Thermal and mechanical stress to the DRG can be significantly reduced in addition to mitigating temperature sensitivity of the DRG chip. The small form can drastically reduce cost and power consumption of the MEMS inertial sensor and enable new applications such as smart munitions, compact and integrated space navigation solutions, with significant potential cost savings over the existing inertial systems.

Abstract: A synchronous detection circuit includes: an offset compensation circuit which generates an offset compensation voltage to compensate an offset voltage superposed on a direct current voltage signal; and a temperature compensation circuit which generates a temperature compensation voltage to compensate variation of a direct current reference voltage that depends on a temperature in a signal path of a sensing circuit. In the circuit, the synchronous detection circuit synchronously detects an alternating current signal, the offset compensation voltage and the temperature compensation voltage are respectively superposed on the alternating current signal which is input into the synchronous detection circuit, and the synchronous detection circuit synchronously detects the alternating current signal on which the offset compensation voltage and the temperature compensation voltage have been superposed.

Abstract: A method of determining a speed of a vehicle during braking is provided. A pressure p in a braking device is determined in accordance with the ideal gas equation p·V=n·R·T. V is the volume V of the brake cylinder, n is the mole number n of the gas in the brake cylinder, R is the gas constant R and T is the temperature T. The brake force F is determined from the pressure p in the brake cylinder and from the impacted piston area A of the brake cylinder in accordance with p = F A , and the instantaneous speed v of the vehicle is determined from a known initial speed vA and from the acceleration a which is determined from the brake force F and the vehicle mass M in accordance with F=M·a.

Abstract: An acceleration sensor for measuring an acceleration comprises a housing including a measuring-plate, which has a first surface. The measuring plate has a second surface in parallel with and opposite to the first surface. A post is bonded via a post-bonding-face to the first surface. A temperature-compensating-element for compensating a temperature-effect caused by a temperature acting on the measuring-plate, is bonded via an element-bonding-face to the second surface of the measuring-plate. In addition, a sensor as described above is in a measuring device.

Abstract: A thermally controlled gas bearing supported inertial measurement unit (IMU) system is provided. The system comprises a sensor assembly enclosing one or more sensors and a plurality of heating elements, wherein each of the plurality of heating elements is proximal to the sensor assembly. The system also comprises a plurality of temperature sensors configured to determine a temperature of a region of the sensor assembly and a control unit configured to adjust a temperature of at least one of the plurality of heating elements based on feedback from the at least one temperature sensor.

Abstract: An apparatus and method for estimating a parameter of interest using a force responsive element comprising, at least in part, a balanced material. The balanced material is temperature insensitive over a specified range of temperatures such that the force responsive element may estimate the parameter of interest by responding to a desired force with relatively little interference due to temperature changes within the specified range of temperatures.

Abstract: An acceleration sensor of the present invention is a heat sensing type acceleration sensor, and includes a heating chip formed with a heating element on a surface thereof, and a sensor chip formed with a thermocouple element on a surface thereof and disposed so that the surface faces the surface of the heating chip.

Abstract: The invention concerns gyrometric measurement compensated as a function of the instantaneous internal temperature of a mechanical resonator in a gyrometric measurement device comprising a loop controlling the amplitude of the resonator vibration and a gyrometric loop delivering a gyrometric signal (S); the gain control (P) of the loop varies as a monotonous function, preferably increasing and of the first order, of the internal temperature of the resonator in a given range of temperature; during a calibrating step, a correspondence is established and stored between the values of the gyrometric scaling factor (Fe) and the gyrometric bias (S0) and the values of the gain control signal (F), that is F(P) and Q(P) respectively; in operation, the following operations are carried out: P?F(P), P?Q(P), and ??est=F(P)·S+Q(P) which is a more precise analog estimate, compensated as a function of the internal temperature of the resonator, of the mechanical rotation of the sensitive axis of the resonator.

Abstract: A sensor unit has a reference base. An acceleration sensor block and angular velocity sensor support rods are arranged on the reference base, using a bottom face and one side face of the reference base as reference faces. Three acceleration sensors, which detect accelerations that act in the directions in which an X-axis, a Y-axis, and a Z-axis extend, are fitted to three faces of the acceleration sensor block, respectively. Three angular velocity sensors, which detect angular velocities about the X-axis, the Y-axis, and the Z-axis, are fitted to boards that are fitted, via rubber bushings serving as vibration-proofing rubber members, to the angular velocity sensor support rods with screws, respectively.

Abstract: An angular velocity detection circuit is connected to a resonator for making excited vibration on the basis of a drive signal and detects an angular velocity. The angular velocity detection circuit includes: a self-vibration component extraction unit that receives, from the resonator, a detection signal including an angular velocity component based on a Coriolis force and a self-vibration component based on the excited vibration and extracts the self-vibration component from the detection signal; a direct-current conversion unit including an integration unit that integrates an output signal of the self-vibration component extraction unit; and a temperature characteristic compensation unit that compensates for a variation due to a temperature in an output signal of the direct-current conversion unit.

Abstract: According to one exemplary embodiment, a virtual turbine speed sensor for a multi-stage turbocharger system of an internal combustion engine is disclosed. The multi-stage turbocharger system includes at least two sequential turbochargers each having a compressor and a turbine. The virtual turbine speed sensor includes a compressor efficiency module, an inter-stage air temperature module, and a turbine speed module. The compressor efficiency module is configured to estimate an efficiency of a compressor of a first of the at least two turbochargers. The inter-stage air temperature module is configured to estimate an inter-stage temperature of air between the at least two compressors. The inter-stage temperature estimate is based at least partially on the efficiency of the compressor of the first turbocharger. The turbine speed module is configured to estimate a speed of a turbine of a second of the at least two turbochargers.

Abstract: A temperature compensation circuit having satisfactory linearity, a trimming circuit including a plurality of temperature gradients, and an acceleration detector having a wide applicable temperature range. A plurality of resistor elements R1 to R4, R5 to R8, R21 to R24, R25 to R28 are connected in series between a power supply voltage line and a ground voltage line. Resistor elements R9 to R14 are connected in series between connection nodes N1 and N3. Resistor elements R29 to R34 are connected in series between connection nodes N2 and N4. The resistor elements R1, R2, R4, R5, R7 to R14, R24, R25 have negative temperature coefficients. The resistor elements R3, R6, R21 to R23, R26 to R34 have positive temperature coefficients. An output terminal NT5 connects a connection node of the resistor elements R13 and R14 and a connection node of the resistor elements R30 and R29.