摘要:
A valve actuator includes a motor coupled to an output shaft that in turn can be coupled to valve elements in a vehicle air passage to move the elements. A position sensing component is provided to produce feedback of actuator motion, and limits of actuator travel for any particular application can be learned in a learning mode and subsequently used in an operating mode to satisfy commands of an engine control module (ECM).
摘要:
The rate of motion of a vehicle air intake valve is measured and used to control the algorithm that controls the valve, such that the control algorithm adapts to the actual conditions in the vehicle as reflected in the actual rate of motion of the valve.
摘要:
A sensing apparatus for determining a property of a fuel such as a gasoline and ethanol blend known as flex fuel includes an acetal plastic tube with an inlet, an outlet and a fuel passage in between. One property of the fuel is a dielectric constant. A pair of sensing plates are placed on opposite sides of the tube leaving the fuel passage unobstructed. A processing circuit on a printed circuit board (PCB) is located near to and is connected with the sensing plates. The circuit applies an excitation signal, senses a capacitance, and generates an output signal indicative of a property of the fuel. The sensed capacitance will increase with increasing concentration of ethanol in the fuel flowing through the passage. A shield for reducing EMI surrounds and encloses the sensing plates and the PCB. An interface connector allows the sensing apparatus to output the capacitance indicative signal to an engine controller or the like.
摘要:
A method for compensating the output of an angular position sensor assembly includes placing a first magnetic field sensor such that it is oriented ninety degrees from a second magnetic field sensor. A magnet is placed so that it is equidistant from the sensors. The magnet is rotated, and as it rotates, the signals output by the sensors are sinusoidal waves that are out of phase with each other by ninety degrees (90°). Accordingly, the signals can be squared and summed to determined a temperature compensation signal.
摘要:
A sensing apparatus for determining a property of a fuel such as a gasoline and ethanol blend known as flex fuel includes an acetal plastic tube with an inlet, an outlet and a fuel passage in between. One property of the fuel is a dielectric constant. A pair of sensing plates are placed on opposite sides of the tube leaving the fuel passage unobstructed. A processing circuit on a printed circuit board (PCB) is located near to and is connected with the sensing plates. The circuit applies an excitation signal, senses a capacitance, and generates an output signal indicative of a property of the fuel. The sensed capacitance will increase with increasing concentration of ethanol in the fuel flowing through the passage. A shield for reducing EMI surrounds and encloses the sensing plates and the PCB. An interface connector allows the sensing apparatus to output the capacitance indicative signal to an engine controller or the like.
摘要:
A method and apparatus for controlling a solenoid-actuated charcoal canister purge valve to control the flow of purge fuel that is supplied via the purge valve to a cylinder of an internal combustion engine. The method includes generating a preselected input duty cycle for use in energizing the solenoid-actuated purge valve that is registered by a microcontroller. The solenoid-actuated purge valve is energized using the input duty cycle to generate an output duty cycle from a current driver in operable communication with the microcontroller. The output duty cycle dictates the quantity of purge fuel flow to the cylinder by controlling the active period of energizing the solenoid. A feedback voltage (Vfb) from the solenoid-actuated purge valve is measured, wherein the feedback voltage (Vfb) corresponds to a feedback duty cycle (DCfb). The microcontroller calculates an error between the input duty cycle (Idc) and the feedback duty cycle (DCfb) and generates a compensated output duty cycle to the current driver based on the error calculated to compensate any deviation. The compensated output duty cycle compensates for any deviation from a linear relationship between the input duty cycle (Idc) and feedback voltage (Vfb), wherein Vfb corresponds to a flow of purge fuel.
摘要:
A method is provided for estimating an electrical parameter of a circuit-under-test (e.g., resistance, capacitance and/or inductance). The method acquires samples during a plurality of charging cycles rather than during just one, which allows an extended overall time period to acquire such samples. The first step involves defining a major sampling period having a plurality of minor sampling periods. A number of steps are performed for each minor sampling period: applying an excitation signal to the circuit-under-test to produce a respective induced, response signal and acquiring a respective sample of the induced signal at a respective predetermined deferral time. In an embodiment where the circuit-under-test includes an unknown capacitance, the excitation signal may be a unit step while an increase in the induced signal is governed by a charging time constant, which itself is indicative of the unknown capacitive. The electrical parameter may be determined based on the acquired samples, which collectively constitute a composite response. The composite response is processed, for example, by fitting it to a normalized capacitive charging curve, to ascertain an estimate of the unknown capacitive.
摘要:
A method for calibrating a flex fuel sensing apparatus having a fuel passage involves the use of a generally solid test blank having a size and shape configured to match that of the fuel passage. The test blank comprises material having a known, predetermined dielectric constant. The test blank is inserted into the fuel passage where the dielectric constant of the test blank is operative to simulate the presence of various gasoline and ethanol fuel blends. The test blank may also comprise a deformable/compressible solid such as rubber where the test blank is compressed during calibration to eliminate air gaps or the like, improving accuracy. The use of the solid test blank reduces complexity compared to using actual gasoline/ethanol blends for calibration as well as reduces post-calibration cleanup.
摘要:
A sensing apparatus for determining a property of a fuel such as a gasoline and ethanol blend known as flex fuel includes an acetal plastic tube with an inlet, an outlet and a fuel passage in between. One property is a dielectric constant. A pair of semi-circular shaped sensing plates are placed around the tube in concentric relation therewith, leaving the fuel passage unobstructed. A processing circuit on a printed circuit board (PCB) is located near and connected with the sensing plates. The circuit applies an excitation signal, senses a capacitance, and generates an output signal indicative of a property of the fuel. A shield for reducing EMI surrounds and encloses the sensing plates and the PCB. The sensed capacitance will increase with increasing concentration of ethanol in the fuel flowing through the passage. An interface connector allows the sensing apparatus to output the indicative signal to an engine controller.
摘要:
A method for compensating signals from an absolute angular position sensor assembly is used in conjunction with an absolute angular position sensor assembly having an input gear coupled to a rotating shaft. The input gear is meshed with an output gear that rotates as the input gear and the shaft rotate. The sensor assembly includes an input gear sensor and an output gear sensor placed in proximity to the input gear and output gear, respectively. The gears are configured so as to be sensed by the sensors. The method includes determining an angular position compensation value that is used to adjust an absolute position of the input gear, which in turn is used to compute the absolute position of the rotating shaft. The angular position compensation value for the revolution N+1 is determined as APCVN+1=(APRSN−AAPIGN)/&agr;+APCVN, wherein APCVN+1 is the angular position compensation value for the revolution N+1, APRSN is the angular position of the rotating shaft for the revolution N, AAPIGN is the adjusted angular position of the input gear for the revolution N, &agr; is a compensation factor that is greater than one, and APCVN is angular position compensation value for the revolution N.