摘要:
A vehicle fleet management information system for identification of location and direction of movement of each vehicle in the fleet in real-time and automatic communication directly with management offices to report its location and heading, and status of predetermined events in which the vehicle may be engaged. One example is a cement delivery truck which monitors location, speed and status information such as start pour, pouring, end pour, wash and leave job, and automatically transmits this information with a management office without requiring affirmative action by the vehicle operator.
摘要:
A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor and converts the differential voltage to current. First and second current sourcing circuits, each including a plurality of current sourcing branches, receives the current and provides current attenuation by switching in and out transistor-based current sourcing branches. The rectifier and differential to single-ended conversion circuit converts the variably attenuated currents to a voltage output.
摘要:
A method for making and vacuum packaging a silicon micromachined motion sensor, such as a gyroscope, at the chip level. The method involves micromachining a trench-isolated sensing element in a sensing chip, and then attaching a circuit chip to enclose the sensing element. Solder bumps serve to attach the circuit chip to the sensing chip, form a hermetic seal to enable vacuum-packaging of the sensor, and electrically interconnect the sensing chip with the circuit chip. Conductive runners formed on the enclosed surface of the circuit chip serve to electrically interconnect the sensing element with its associated sensing structures.
摘要:
In accordance with the teachings of the present invention, a programmable integrated transducer amplifier circuit is provided which receives differential outputs from a transducer, such as a pressure or accelerometer transducer. The programmable integrated transducer amplifier circuit includes binary adjustable circuits that are programmed in response to binary coded signals. The binary adjustable circuits generate binary weighted currents that are employed to adjust the operating characteristics of the amplifier circuit. The binary coded signals are received from a programmable memory array which includes a plurality of memory cells that store binary information. Each of the memory cells are programmed when coupled to a programming signal. Additionally, the memory array has pretest capability for testing outputs of the memory cells prior to permanently programming the respective memory cells. Additionally, the integrated transducer amplifier circuit automatically compensates for variations in the operating temperature of the amplifier circuit. The method of temperature compensation is accomplished by operating the programmable integrated transducer amplifier circuit at a first temperature such that a temperature compensation voltage is "nulled" or is forced to equal zero. Thereafter, the integrated transducer amplifier circuit is operated at other temperatures such that the temperature compensation voltage is generated in a manner representing the difference between the first operating temperatures and the current operating temperature.
摘要:
A motion sensor for sensing motion or acceleration of a body, such as the type used in onboard automotive and aerospace safety control system, navigational system or active suspension control system. The motion sensor includes a support frame, a bridge projecting from the support frame, and a proof mass suspended from the support frame by the bridge so as to enable the proof mass to respond to an input force imposed on the motion sensor. The bridge is provided with a strain sensing element that generates an acceleration signal in response to a deflection of the proof mass. The motion sensor further includes a structural feature capable of compensating for mechanically and thermally induced strains imposed on the motion sensor by generating a compensation signal in response to such strains. Finally, the sensor includes circuitry for detecting the acceleration and compensation signals and canceling the compensation signal from the acceleration signal, so as to produce an output signal that more closely corresponds to the input force on the proof mass than does the acceleration signal.
摘要:
An analog signal gain circuit includes an input receiving an analog input signal defined by an ac signal component due to a driving force and a dc offset component independent of the driving force and an output providing an analog output signal defined by an amplified representation of the analog input signal and a dc offset component corresponding to a reference signal. A digital/analog feedback circuit includes a comparator having the reference signal as a switching threshold connected to an up/down counter having a number of digital outputs. The outputs of the up/down counter are connected to a D/A converter which converts the digital count to an analog feedback signal. The feedback signal is provided to the input of the analog signal gain circuit to minimize variations in the dc offset signal component of the analog output signal by compensating for the dc offset signal component of the analog input signal. The up/down counter is clocked at a slow rate to thereby provide a long time constant for minimizing the dc offset signal component.
摘要:
A memory cell having programming voltage margin verification is provided. The memory cell includes a voltage comparator having a differential input with first and second inputs and bias circuitry for generating a differential input voltage. A voltage offset is applied to the second input of the comparator to provide an input offset voltage. A programming voltage is received for programming the memory cell and the memory cell provides an output signal. To verify an unprogrammed state voltage margin of the memory cell, a margin detection circuitry receives a verification check signal and the output is monitored to determine whether the unprogrammed state voltage margin is proper. To verify a proper programmed state voltage margin of the memory cell, current is sensed through the programming input and a determination of a proper programmed state voltage margin is determined as a function of the sensed current.
摘要:
A variable reluctance sensor interface module having a variable attenuation circuit and a rectifier and differential to single-ended conversion circuit for operating in a current mode to attenuate a differential input voltage. The variable attenuation circuit receives an input differential voltage from a magnetic sensor and converts the differential voltage to current. First and second current sourcing circuits, each including a plurality of current sourcing branches, receive the current and provides variable current attenuation by switching in and out transistor-based current sourcing branches. The rectifier and differential to single-ended conversion circuit converts the variably attenuated currents to a voltage output.
摘要:
A vehicle fleet management information system identifies location and direction of movement of each vehicle in a fleet in real-time, and automatically reports such information, as well as status of predetermined events in which the vehicle is engaged, directly to the fleet manager. Each fleet vehicle has an assigned time slot to transmit its reporting information over a communications network without interfering with transmissions from other vehicles in their own respective time slots. A timing control phase lock loop (PLL) provides precise time synchronization for timing corrections from a global positioning system (GPS) based time reference. A dual band full-duplex interface of the network has TDMA on one-half and broadcast on the other half. Microprocessor time processing units in components of the network perform precise clock synchronization. Space diversity performed on received vehicle transmitted messages avoids data corruption. Different vehicles have different periodic transmission intervals, by dynamically allocating the slots for various update rates. Auxiliary reporting slots enable prompt reporting of important data by the respective vehicle transmitters independent of the slower periodic transmission intervals.
摘要:
A media-compatible sensing structure (210) that employs strain-sensing elements (222) formed in or on a silicon chip (212). The sensor (210) generally includes a metal body (214) having a diaphragm (216) and an edge (226) formed by an abrupt change in the thickness of the metal body (214) in a direction normal to the diaphragm (216). The silicon chip (212) is secured directly to the metal diaphragm (216) and has at least one strain-sensing element (222) aligned with the edge (226) of the body (214) in the direction normal to the diaphragm (216), such that movement of the diaphragm (216) induces strain in the silicon chip (212) that is localized at the strain-sensing element (222). The chip (212) preferably includes a groove (234) in its surface (212) facing the diaphragm (216) and between the strain-sensing element (222) and the metal body (214), such that strain induced in the chip (212) by movement of the diaphragm (216) is further concentrated in the region of the chip (212) containing the strain-sensing element (222). The chip (212) is preferably attached to the metal diaphragm (216) with a bonding material (236). To promote adhesion of the chip (212) to the diaphragm (216), the chip (212) preferably has recesses (240) in its surface facing the diaphragm (216) to create an interlocking effect between the bonding material (236) and the chip (212).