摘要:
A microelectromechanical (MEMS) switch includes a substrate, a force-activated latching mechanism, and a spring-loaded shuttle. The latching mechanism has a proximal end and a distal end. In an embodiment, the latching mechanism includes two flexible latch arms each fixed at or about a proximal end and having a free distal end, and a connector connecting the latch arms. The spring-loaded shuttle includes a shuttle portion including a portion configured for engaging portions of the latch arms. The shuttle portion further being configured to translate about the substrate. The latching mechanism and the shuttle may be configured to include an electrical contact layer such that when the latch arms are engaged with the shuttle portion, a closed electrical circuit can be formed.
摘要:
An automatic clutch controller for a vehicle that reduces the oscillatory response to clutch engagement. The automatic clutch controller receives inputs from an engine speed sensor and a transmission input speed sensor and develops a clutch actuation signal controlling a clutch actuator from disengaged to fully engaged. The clutch engagement signal at least partially engages the friction clutch in a manner to cause the measured transmission input speed to asymptotically approach engine speed employing an approximate inverse model of this oscillatory response. The automatic clutch controller preferably includes a slip integral function and a differential engine speed function, which together adaptively adjust clutch engagement corresponding to vehicle loading. The automatic clutch controller includes a prefilter and a compensator constructed to reduce the need for detailed particularization for individual vehicles or vehicle models.A lag compensation function in the compensator adds robustness to the system by increasing low frequency gain. A freeze function suspends operation of the slip integral, the prefilter and the compensator during engine deceleration or when throttle position is high and engine speed is low, to moderate or stop clutch advance to prevent engine overloading.
摘要:
An automatic clutch controller for a vehicle that reduces the oscillatory response to clutch engagement. The automatic clutch controller receives inputs from an engine speed sensor and a transmission input speed sensor and develops a clutch engagement signal controlling a clutch actuator between from disengaged to fully engaged. The clutch engagement signal at least partially engages the friction clutch in a manner to cause the measured transmission input speed to asymptotically approach a reference speed employing an approximate inverse model of this oscillatory response. In a launch mode, corresponding to normal start of the vehicle, the reference speed is the measured engine speed. In a creep mode, corresponding to slow speed creeping of the vehicle, the reference speed is a creep speed reference based on the throttle setting and the engine speed. The two modes are selected based upon the throttle setting. The automatic clutch controller preferably includes an integral error function and a differential engine speed function, which together adaptively adjust clutch engagement corresponding to vehicle loading.
摘要:
A torque motor and throttle body are integrated within a single assembly for application with an internal combustion engine charge air inlet. The butterfly valving element of the throttle body and rotor of the motor are mounted on a common shaft, the position of which is established by a fly-by-wire control circuit. The control circuit includes a driver which selectively energizes the motor in response to the simultaneous receipt of both duty cycle and pulse with information. The control circuit further provides redundant outputs and transducers to enhance system failsafing.
摘要:
Pulse frequency modulation is used to control brakes and clutches which are operated by fluid pressure actuators controlled by electrically actuated solenoid valves. Short pulse periods for all duty cycles are generated by feedback from the solenoid valve or from the actuator. In one circuit an electrical control triggers a flip-flop which starts solenoid current. Solenoid movement results in back-emf and its effects on the solenoid flux field or current is detected and used as a feedback signal to reset the flip-flop to thereby turn off the current as soon as the valve is operated. In another circuit, a computer control emits a command for a certain pulse period. Actuator pressure or position is monitored to produce a feedback signal to the computer. If the signal is not received, the pulse period is increased for the next pulse command so that a sufficient pulse period will be found. If the magnitude of the actuator response exceeds a threshold, the pulse period is decreased for the next pulse command. Pulse width modulation may also be improved by the same technique for minimizing the pulse period at the lowest duty cycles and yet assuring actuation.
摘要:
An inverter is connected between a source of DC power and a three-phase AC induction motor, and a micro-processor-based circuit controls the inverter using pulse width modulation techniques. In the disclosed method of pulse width modulation, both edges of each pulse of a carrier pulse train are equally modulated by a time proportional to sin .THETA., where .THETA. is the angular displacement of the pulse center at the motor stator frequency from a fixed reference point on the carrier waveform. The carrier waveform frequency is a multiple of the motor stator frequency. The modulated pulse train is then applied to each of the motor phase inputs with respective phase shifts of 120.degree. at the stator frequency. Switching control commands of electronic switches in the inverter are stored in a random access memory (RAM) and the locations of the RAM are successively read out in a cyclic manner, each bit of a given RAM location controlling a respective phase input of the motor. The DC power source preferably comprises rechargeable batteries and all but one of the electronic switches in the inverter can be disabled, the remaining electronic switch being part of a "flyback" DC-DC converter circuit for recharging the battery.
摘要:
Apparatus is disclosed for converting input step and direction commands from an external control source into stator winding drive current signals for a permanent magnet stepper motor. A translator circuit, having inputs coupled to the external control, generates sequential stator winding pulse enabling signals for transmission to a chopper-controlled power drive circuit. The chopper control features the sharing of a single chopper power switch by pairs of stator windings. The power drive circuit provides a winding current path to a reverse voltage supply upon initiation of winding current turn-off to enhance switching speed. A dual level current reference is generated in a current regulator circuit and compared with instantaneous stator winding currents to control the conduction states of the chopper power switches. Dual reference levels are established for idle versus accelerating or decelerating motor states, respectively. The translator circuit includes means for inhibiting chopper power switch conduction independently of the current regulator reference level comparison whenever the translator is switching drive current among stator windings, thereby decreasing power dissipation due to transients.
摘要:
An invention is disclosed to divide a segmented image of an occupant into an upper torso image and a lower torso image. An occupant labeling heuristic can identify each pixel within the segmented image as an upper torso pixel or a lower torso pixel. A k-means module can provide an initial pixel classification by comparing the distance between the particular pixel and an estimated midpoint on the upper torso with the distance between the particular pixel and an estimated midpoint on the lower torso. The iterative parameters estimator can update the mean values for the upper torso and lower torso by performing a conditional likelihood heuristic. Pixels can then be classified as either upper or lower torso pixels by comparing a Mahalonobis distance for each torso. Airbag-related applications can then use the upper torso image to generate occupant characteristics relevant to airbag-related applications.
摘要:
A supercharger clutch system has a clutch housing (52) in which a clutch pack (84) is disposed to transmit torque from an input, such as a pulley (66), to one of the timing gears (58). The clutch pack (84) is disposed within a cage (92), having a spring seat member (98) adjacent thereto. A set of springs (104) biases the seat member and the clutch cage (92) to engage the clutch pack (84). On the opposite side, axially, of the clutch pack there is a piston (76) including a portion (80) surrounding the clutch cage (92) and engaging the seat member (98). The piston (76) and the clutch housing (52) define a pressure chamber (106) which, when pressurized, causes movement of the piston in a direction compressing the springs (104) and disengaging the clutch pack. The invention provides a method of controlling the clutch system by means of an electrohydraulic valve (110) which can communicate the pressure chamber (106) to either high pressure (112) or low pressure (132). The valve (110) is controlled by sensing throttle position (141) and modifying a command signal (130) to a coil (126) of the valve (110) in response to the throttle position (141), so that the rate of clutch engagement may be modulated in response to throttle position.
摘要:
An automatic clutch controller for a vehicle that reduces the oscillatory response to clutch engagement. The automatic clutch controller receives inputs from an engine speed sensor and a transmission input speed sensor and develops a clutch actuation signal controlling a clutch actuator between from disengaged to fully engaged. The clutch engagement signal at least partially engages the friction clutch in a manner to cause the measured transmission input speed to asymptotically approach a reference speed employing an approximate inverse model of this oscillatory response. In a launch mode, corresponding to normal start of the vehicle, the reference speed is the measured engine speed. In a creep mode, corresponding to slow speed creeping of the vehicle, the reference speed is a creep speed reference based on the throttle setting and the engine speed. The two modes are selected based upon the throttle setting. The automatic clutch controller preferably includes an integral error function and a differential engine speed function, which together adaptively adjust clutch engagement corresponding to vehicle loading. The automatic clutch controller includes a prefilter and a compensator constructed to reduce the need for detailed particularization for individual vehicles or vehicle models.