JP4198544B2 - Electronic throttle control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention has a non-contact type sensor that detects, by a magnetoelectric transducer, an opening amount of a throttle valve installed in an intake pipe of an automobile engine and an accelerator opening amount proportional to an accelerator operation, and resets the non-contact type sensor. The present invention relates to an electronic throttle control device that prohibits feedback control of the throttle opening position when a state is detected.
[0002]
[Prior art]
In the conventional rotation angle detection sensor, if the outputs from the two Hall ICs constituting the throttle opening sensor are in the use range of the throttle opening and their relative relationship is within a predetermined error range, both Hall ICs are used. If it is normal, on the other hand, the upper clamp voltage or the lower clamp voltage, and the relative relationship thereof exceeds a predetermined error range, it can be determined that an abnormality has occurred in at least one of the Hall ICs. If the output is within the ECU-side fail determination voltage range, it can be determined that an abnormality has occurred between the throttle opening sensor and the ECU. Thereby, in addition to the abnormality in all the use areas including the high opening area side of the throttle opening, an abnormality such as a connection state between the throttle opening sensor and the ECU can be determined (for example, refer to Patent Document 1).
[0003]
[Patent Document 1]
JP 2001-174212 A (first page, FIG. 4)
[0004]
[Problems to be solved by the invention]
In an electronic throttle control device that controls the drive of a throttle valve using a motor, failure of the throttle opening sensor and the accelerator opening sensor is a serious problem, which may be caused by factors such as an abnormal increase in engine speed and abnormal acceleration of automobiles. It can be.
[0005]
However, the rotation angle detection sensor as described above is composed of a signal processing circuit that converts an analog signal detected by the Hall IC into a digital signal, performs temperature correction, offset, gain, output clamp processing, and converts the analog signal again. Since the signal processing circuit uses an A / D converter, a DSP (digital signal processor), a D / A converter, etc., when the supply voltage to the sensor falls below a predetermined value, the DSP In the voltage state immediately before the reset is applied and the sensor output voltage value sticks to the sensor supply voltage value, or immediately before shifting to the reset, the sensor output voltage value becomes a fixed state, which causes a problem. If the sensor output voltage sticks to the sensor supply voltage due to a decrease in the sensor supply voltage during engine idling, the throttle valve is pushed to the fully closed position by feedback control of the throttle opening position, and the fully closed stopper There are problems such as wear of the position, deformation and damage of the reduction gear, and engine stall due to pressing of the throttle valve to the fully closed position.
[0006]
In addition, the sensor output voltage value may be fixed immediately before the reset transition. In this case, when the throttle target opening voltage increases above the sensor output voltage value, the throttle valve position is controlled by feedback control of the throttle opening position. Is pushed to the fully open position, leading to an abnormal increase in engine speed and abnormal acceleration of the car.
[0007]
The present invention has been made to solve the above-described problems, and an object of the present invention is to detect an abnormality before an abnormality of a sensor output voltage occurs due to a decrease in supply voltage to a non-contact type sensor. An electronic throttle control device capable of avoiding deformation, breakage, engine stall, etc. of the reduction gear due to unnecessary pressing of the throttle valve to the fully closed position by feedback control of the opening position is obtained.
[0008]
[Means for Solving the Problems]
The electronic throttle control device according to the present invention drives a non-contact type accelerator opening sensor that detects an accelerator pedal operation amount and outputs an accelerator opening signal, and a throttle valve that adjusts an intake air amount to the engine. A throttle actuator having a motor; a non-contact throttle opening sensor that detects the opening of the throttle valve and outputs a throttle opening signal; battery voltage detection means that detects a voltage of the battery; and a sensor supply voltage. Based on the sensor power supply voltage detection means to detect, the accelerator opening signal and the engine speed signal, the target throttle opening position of the throttle valve is calculated, and the opening position of the throttle valve is the target throttle opening position The throttle bar based on the throttle opening signal. Throttle control means for performing feedback control of the opening position of the battery, and the throttle control means includes a battery voltage detected by the battery voltage detection means and a first voltage that is approximately ½ of the normal operating voltage of the battery voltage. When the battery voltage is lower than the first predetermined voltage and when the engine is started, and when the battery voltage is lower than the first predetermined voltage and not when the engine is started. If the battery voltage drop continuation time when the battery voltage is less than the first predetermined voltage does not exceed the first predetermined time, feedback control of the throttle valve opening position is performed. A sensor which is prohibited and detected by the sensor power supply voltage detection means when the battery voltage is equal to or higher than the first predetermined voltage. A supply voltage is compared with a second predetermined voltage lower than the first predetermined voltage, and the sensor supply voltage is less than the second predetermined voltage, and the sensor supply voltage is the second predetermined voltage. If the sensor supply voltage drop continuation time that is less than the second predetermined time shorter than the first predetermined time is not exceeded, feedback control of the throttle valve opening position is prohibited. When the battery voltage is less than the first predetermined voltage, and when the engine is not started, and when the battery voltage drop duration exceeds the first predetermined time, the battery It is determined that the voltage is abnormal, and the throttle valve is controlled to return to the retracted travel opening position as the retreat travel process, the battery voltage is equal to or higher than the first predetermined voltage, and the sensor supply voltage is If it is less than the second predetermined voltage and if the sensor supply voltage decrease duration exceeds the second predetermined time, it is determined that the sensor supply voltage is abnormal, Control to return the throttle valve to the retracted travel opening position To do.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
An electronic throttle control apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an electronic throttle control apparatus according to Embodiment 1 of the present invention. In addition, in each figure, the same code | symbol shows the same or equivalent part.
[0010]
In FIG. 1, the electronic throttle control device includes an accelerator opening sensor (APS) 1 that detects an accelerator pedal position as an accelerator opening, and various throttle control means that controls intake air amount of an engine (not shown). An electronic control unit (ECU) 2 for controlling the engine, a throttle actuator 3, and a throttle opening sensor (TPS) 4 for detecting the throttle valve position as a throttle opening.
[0011]
The electronic control unit (ECU) 2 has at least a microcomputer 5 and a drive circuit 6. A microcomputer (throttle control means) 5 inputs an accelerator opening signal from the accelerator opening sensor 1 and at least an engine speed signal from an engine speed sensor (not shown), and opens a target throttle opening of a throttle valve 34 described later. The throttle position is calculated, and the throttle position feedback control (for example, PID control) is performed so that the throttle position signal input from the throttle position sensor 4 matches the target throttle position. In other words, the microcomputer (throttle control means) 5 outputs a control signal (for example, a DUTY signal at the time of PWM driving) to the drive circuit 6 by calculation of feedback control, and the drive circuit 6 supplies a desired signal to the motor 31 of the throttle actuator 3. A drive current is supplied to drive the throttle valve 34.
[0012]
In the throttle actuator 3, the driving force of the motor 31 is transmitted to the throttle shaft 33 via the reduction gear 32 in the reduction gear constituted by a resin gear (not shown) and the like, and the throttle valve 34 is driven.
[0013]
The throttle opening sensor 4 includes two Hall ICs 41 and 42, which will be described later, as double-contact and non-contact detection elements arranged integrally with a sensor cover (not shown), and these Hall ICs 41 and 42 and the outside. A lead frame (not shown) made of a conductive thin metal plate for electrically connecting the ECU 2 to the ECU 2, a cylindrical permanent magnet (not shown) that is a magnetic field generation source coupled to the throttle shaft 33, and a Hall IC 41 , 42 is composed of a split stator (not shown) made of a magnetic material that concentrates the magnetic flux to 42. When the two Hall ICs 41 and 42 generate an N-pole or S-pole magnetic field on their magnetosensitive surfaces, an electromotive force ((+) potential is generated by the N-pole magnetic field and (+) potential by the N-pole magnetic field ( -) It is arranged on the inner peripheral side of the permanent magnet so as to generate potentials.
[0014]
FIG. 2 is a diagram showing a schematic configuration of an input I / F circuit of the throttle opening sensor and the accelerator opening sensor of the electronic throttle control device according to Embodiment 1 of the present invention.
[0015]
In FIG. 2, the battery voltage is supplied from the battery 7 to the ECU 2 via an ignition switch (not shown), A / D converted by an A / D converter (not shown) in the microcomputer 5, and supplied to the battery voltage detection means 51. Entered. In the ECU 2, the battery voltage is input, and a constant voltage (for example, 5 V) generated by a constant voltage circuit is supplied to the throttle opening sensor (TPS) 4 as the sensor supply voltage 43, and the sensor power supply voltage 44 ( = Sensor supply voltage 43) is input to the sensor power supply voltage detection means 52.
[0016]
For example, 5 V is supplied as the sensor supply voltage 43 to the two Hall ICs (TPS1, TPS2) 41, 42 in the throttle opening sensor (TPS) 4. The first and second throttle opening voltages 45 and 46 are detected by detecting the rotation of the throttle valve 34 as the change in magnetic flux density caused by the rotation of the permanent magnet connected to the throttle shaft 33 on the magnetic sensing surfaces of the Hall ICs 41 and 42. And is input to the first throttle opening voltage detecting means 53 and the second throttle opening voltage detecting means 54 via an A / D converter (not shown) in the microcomputer 5.
[0017]
Similarly to the throttle opening sensor (TPS) 4, the accelerator opening sensor (APS) 1 includes two Hall ICs (APS1, APS2) 11 and 12 as non-contact detection elements. The second accelerator opening voltage 13, 14 is generated, and the first accelerator opening voltage detecting means 55 and the second accelerator opening voltage detection are detected via an A / D converter (not shown) in the microcomputer 5. Input to means 56.
[0018]
FIG. 3 is a diagram showing an internal configuration of a non-contact type throttle opening sensor (Hall IC) of the electronic throttle control device according to Embodiment 1 of the present invention.
[0019]
In FIG. 3, an angle detection value corresponding to the throttle opening of the throttle valve 34 detected by the rotation angle detector 81 using a Hall element is input to the A / D converter 82. The Hall IC 8 has a temperature detection unit 86. A temperature detection value detected by the temperature detection unit 86 is input to a temperature characteristic correction circuit 87, and a preset value written in an EEPROM (Electrical Erasable Programmable ROM) 85 in advance. Is input to the temperature correction circuit 87 and the detected temperature value is corrected and then input to the A / D converter 82.
[0020]
The angle detection value and the corrected temperature detection value input to the A / D converter 82 are digitally converted and then input to a DSP (Digtal Signal Processor) 83. A setting value written in advance in the EEPROM 85 is input in the DSP 83, and offset adjustment, gain adjustment, and clamp adjustment are performed based on the setting value. The offset adjustment adjusts the offset of the sensor output voltage with respect to the throttle opening, the gain adjustment adjusts the slope of the sensor output voltage with respect to the throttle opening change, and the clamp adjustment adjusts the upper limit voltage value and lower limit voltage of the sensor output voltage. Value is set. The value adjusted in the DSP 83 is output to the D / A converter 84 and converted into an analog signal, and then input to the ECU 2 as the throttle opening voltage from the output terminal of the Hall IC.
[0021]
Next, the operation of the electronic throttle control device according to the first embodiment will be described with reference to the drawings.
[0022]
FIG. 4 is a diagram showing an output characteristic of the throttle opening sensor (TPS) of the electronic throttle control device according to Embodiment 1 of the present invention.
[0023]
In FIG. 4, the horizontal axis represents the throttle operation region (throttle opening), and the vertical axis represents the sensor output (output voltage). The output voltage VTPS1 (solid line) of the first throttle opening sensor (TPS1) 41 outputs a voltage value proportional to the throttle opening, and the output voltage VTPS2 (broken line) of the second throttle opening sensor (TPS2) 42. Is a characteristic that outputs a voltage value inversely proportional to the throttle opening.
[0024]
FIG. 5 is a diagram showing output characteristics of the accelerator opening sensor (APS) of the electronic throttle control device according to Embodiment 1 of the present invention.
[0025]
In FIG. 5, the horizontal axis represents the accelerator pedal operation area (accelerator opening), and the vertical axis represents the sensor output (output voltage). The output voltage VAPS1 (solid line) of the first accelerator opening sensor (APS1) 11 outputs a voltage value proportional to the accelerator opening, and the output voltage VAPS2 (broken line) of the second accelerator opening sensor (APS2) 12 Is a characteristic of outputting a voltage value proportional to the accelerator opening offset to the minus (−) side with respect to the output voltage VAPS1 of the first accelerator opening sensor (APS1) 11.
[0026]
FIG. 6 is a timing chart showing a change in the output voltage of the throttle opening sensor when the battery voltage of the electronic throttle control device according to Embodiment 1 of the present invention decreases.
[0027]
In FIG. 6, the horizontal axis represents time, and the vertical axis represents voltage. When the battery voltage VB (dotted line) falls below the first predetermined voltage VBL (for example, 6V) at time t1, the sensor supply voltage VS (broken line) also falls, and accordingly, the output voltage VTPS1 (solid line) of the throttle opening sensor 41 Begins to decline. Further, when the sensor supply voltage VS drops below a second predetermined voltage VSL (for example, 4 V) at the time t2 due to the drop in the battery voltage VB, a reset acts on the DSP 83 of the internal circuit of the non-contact sensor shown in FIG. The output voltage VTPS1 of the opening sensor 41 rapidly increases and sticks to the sensor supply voltage VS (VTPS1 = VS). The microcomputer 5 outputs a control signal (for example, a DUTY signal for PWM drive) to drive the throttle valve 34 in the fully closed direction to the drive circuit 6 by feedback (F / B) control of the throttle opening position. In the actuator 3, the throttle valve 34 collides with the fully closed stopper position, and an excessive stress is applied to the resin gear in the speed reducer, which may cause deformation of the resin gear or damage of the resin gear in the worst case. If the battery voltage VB drops abnormally when the engine is started, the throttle valve 34 is pressed to the fully closed position, and the amount of intake air to the engine is not secured, resulting in engine start failure.
[0028]
FIG. 7 is a timing chart showing the voltage change of the sensor output voltage of the throttle opening sensor when the sensor supply voltage of the electronic throttle control device according to Embodiment 1 of the present invention has some abnormality.
[0029]
In FIG. 7, the horizontal axis represents time, and the vertical axis represents voltage. Although the battery voltage VB (dotted line) is a normal operation voltage (for example, 14 V), the sensor supply voltage VS (broken line) suddenly becomes the second predetermined voltage VSL at time t3 due to some abnormality (for example, a constant voltage circuit abnormality). When the voltage drops below (for example, 4 V), the reset acts on the DSP 83 of the internal circuit of the non-contact sensor shown in FIG. 3 in the same manner as described above, and the output voltage VTPS1 (solid line) of the throttle opening sensor 41 increases rapidly and the sensor supply voltage Stick to VS (VTPS1 = VS). The microcomputer 5 outputs a control signal (for example, a DUTY signal for PWM drive) to drive the throttle valve 34 in the fully closed direction to the drive circuit 6 by feedback (F / B) control of the throttle opening position. At t4, the throttle valve 34 collides with the fully closed stopper position, and an excessive stress is applied to the resin gear in the speed reducer, which may cause deformation of the resin gear or, in the worst case, damage of the resin gear. Since 34 is pressed to the fully closed position, an engine stall occurs.
[0030]
FIG. 8 is a flowchart showing the operation of the electronic throttle control device according to Embodiment 1 of the present invention when the voltage is abnormal.
[0031]
FIG. 8 shows a processing flow for sticking the output voltage VTPS of the non-contact type throttle opening sensor 4 to the sensor supply voltage VS due to a decrease in the battery voltage VB or a decrease in the sensor supply voltage VS. .
[0032]
In step 101, the microcomputer (throttle control means) 5 compares the battery voltage VB detected by the battery voltage detection means 51 with a first predetermined voltage VBL that is approximately ½ of the normal operating voltage of the battery voltage VB, If VB <VBL is not satisfied (VB ≧ VBL), the process proceeds to the next step 102, and if VB <VBL, the process proceeds to step 104.
[0033]
Next, in step 102, the sensor supply voltage VS detected by the sensor power supply voltage detection means 52 is compared with the second predetermined voltage VSL lower than the first predetermined voltage VBL, and VS <VSL is not satisfied (VS ≧ VSL). If so, the process proceeds to the next step 103, and if VS <VSL, the process proceeds to step 109.
[0034]
Next, in step 103, a throttle opening position feedback (F / B) control process is performed. That is, the target throttle opening position of the throttle valve 34 is calculated based on the accelerator opening signal and the engine speed signal, and the throttle opening signal is set so that the opening position of the throttle valve 34 matches the target throttle opening position. Based on the above, feedback control of the opening position of the throttle valve 34 is performed.
[0035]
In step 104, it is determined whether or not the engine is starting (for example, ON / OFF of the cranking switch). If the engine is starting, the process proceeds to step 108. If not, the process proceeds to the next step 105.
[0036]
Next, in step 105, it is determined whether or not the battery voltage drop (VB <VBL) duration Tb exceeds a first predetermined time Tf1 (for example, 10 seconds). Proceed to 106, and if not exceeded, proceed to step.
[0037]
Next, in steps 106 to 107, it is determined that the battery voltage VB is abnormal, the energization to the throttle actuator 3 is cut off (for example, the relay is turned off) as the retreat travel process, and the throttle valve 34 is opened for retreat travel. Return to the position and limit engine output for evacuation travel.
[0038]
In step 108, the throttle opening position feedback (F / B) control is prohibited. The throttle actuator 3 has a mechanism that mechanically stops at a preset travel opening position when the motor 31 is de-energized. When the microcomputer 5 prohibits feedback control of the throttle opening position, the throttle actuator 3 is driven. A predetermined control signal (for example, DUTY value = 0%) is output to the circuit 6 to return the throttle valve 34 to the retreat travel opening position and wait for the engine to start.
[0039]
In step 109, it is determined whether or not the sensor supply voltage drop (VS <VSL) duration Ts exceeds a second predetermined time Tf2 (for example, 0.5 seconds). If it has exceeded, go to the next step 110.
[0040]
Next, in step 110, the microcomputer (throttle control means) 5 determines that the sensor supply voltage VS is abnormal, and performs a retreat travel process in step 107.
[0041]
As the non-contact type throttle opening sensor 4, the output of the second throttle opening sensor (TPS2) has an output characteristic with an offset with respect to the output of the first throttle opening sensor (TPS1). The outputs of the first throttle opening sensor (TPS1) and the second throttle opening sensor (TPS2) may have the same characteristics, and the same effect can be obtained.
[0042]
That is, by prohibiting the feedback control of the throttle opening position by the microcomputer (throttle control means) 5 (step 108), the throttle opening is caused by the sticking of the sensor output voltage to the sensor supply voltage due to the supply voltage drop to the non-contact sensor. Since the throttle valve 34 is not pressed against the fully closed stopper position by the feedback control of the degree position, a predetermined amount of air can be sucked at the time of engine start, engine startability is ensured, and the engine is operated during engine operation. Stall can be avoided and the throttle valve 34 is not unnecessarily pressed against the fully closed stopper position, so that the fluctuation of the throttle fully closed position due to wear of the fully closed stopper material is suppressed, and the reduction gear 32 of the throttle actuator 3 is made of resin. When using this gear, the stopper Durability can be prevented deformation and damage of the gears due to contact is such an effect is ensured.
[0043]
Further, since the detection of the reset state of the non-contact sensor is performed by detecting the battery voltage or the supply voltage to the non-contact sensor, it can be detected with a simple configuration, and the cost increase can be suppressed.
[0044]
Further, the throttle actuator 3 has a mechanism for mechanically stopping at a retracted travel opening position set in advance when the actuator is not energized, and the microcomputer (throttle control means) 5 prohibits feedback control of the throttle opening position. At this time, since a predetermined control signal is output to the throttle actuator 3, a temporary abnormality such as a supply voltage abnormality to the non-contact sensor or a contact failure of the power supply side terminal or the ground side terminal of the sensor is detected. In addition, it is possible to avoid the above-described adverse effects caused by pressing the throttle to the fully closed position and to continuously monitor the abnormality of the power supply system to the throttle actuator 3 because it is not necessary to cut off the power supply to the throttle actuator 3. is there.
[0045]
Further, when it is determined that the battery voltage VB and the sensor supply voltage VS are abnormal in steps 106 and 110, the throttle valve 34 is returned to the opening position for retreat travel so that retreat travel is performed, so safety during retreat travel is ensured. There is an effect that can be done.
[0046]
Embodiment 2. FIG.
An electronic throttle control apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings. The configuration of the electronic throttle control device according to the second embodiment of the present invention is the same as that of the first embodiment.
[0047]
The operation of the electronic throttle control apparatus according to Embodiment 2 of the present invention will be described with reference to the drawings.
[0048]
FIG. 9 is a flowchart showing the operation of the electronic throttle control device according to Embodiment 2 of the present invention when the voltage is abnormal.
[0049]
FIG. 9 shows a processing flow for sticking the output voltage of the non-contact accelerator opening sensor 1 to the sensor supply voltage VS due to the decrease in the battery voltage VB.
[0050]
In step 201, the microcomputer (throttle control means) 5 compares the battery voltage VB detected by the battery voltage detection means 51 with a first predetermined voltage VBL that is approximately ½ of the normal operating voltage of the battery voltage VB. If VB <VBL, the process proceeds to the next step 202. If VB <VBL is not satisfied (VB ≧ VBL), the process proceeds to step 207.
[0051]
Next, in step 202, it is determined whether or not the engine is starting (for example, ON / OFF of the cranking switch). If the engine is starting, the process proceeds to step 206; move on.
[0052]
Next, in step 203, it is determined whether or not the battery voltage drop (VB <VBL) duration Tb exceeds a first predetermined time Tf1 (for example, 10 seconds). Proceed to 204, and if not exceeded, proceed to step 206.
[0053]
Next, in step 204, it is determined that the battery voltage VB is abnormal.
[0054]
Next, in step 205, as the retreat travel process, the power supply to the throttle actuator 3 is cut off (for example, the relay is turned off), the throttle valve 34 is returned to the retreat travel opening position, and the engine output for retreat travel is limited. .
[0055]
In step 206, a predetermined value (for example, accelerator fully closed position voltage) is selected as the accelerator opening voltage VAPS (accelerator opening signal), the target opening position of the throttle is calculated based on the selected value, and the process proceeds to step 208.
[0056]
In step 207, the output voltage VAPS1 of the first accelerator opening sensor 11 is selected as the accelerator opening voltage VAPS (accelerator opening signal), the target opening position of the throttle is calculated based on this, and the process proceeds to step 208.
[0057]
Next, in step 208, the microcomputer (throttle control means) 5 performs a throttle opening position feedback (F / B) control process. That is, the target throttle opening position of the throttle valve 34 is calculated based on the accelerator opening signal (accelerator opening voltage VAPS) and the engine speed signal, and the opening position of the throttle valve 34 matches the target throttle opening position. Thus, feedback control of the opening position of the throttle valve 34 is performed based on the throttle opening signal.
[0058]
That is, in step 206, the throttle target opening position is calculated by setting the accelerator opening amount to a predetermined value. There is an effect that it is possible to avoid an engine speed increase due to the throttle target opening instruction. In addition, there is an effect that it is possible to avoid an abnormal increase in rotational speed at the time of starting the engine due to a cryogenic temperature, a deteriorated battery, or the like.
[0059]
If it is determined in step 204 that the battery voltage VB is abnormal, the throttle valve 34 is returned to the retreat travel opening position so that retreat travel is performed. Therefore, the sensor output when the non-contact sensor is reset when the battery voltage is abnormal. There is an effect that it is possible to avoid the engine speed increase due to the abnormal throttle target opening instruction accompanying the voltage sensor supply voltage tension and to ensure the safety at the time of evacuation traveling.
[0060]
Embodiment 3 FIG.
An electronic throttle control apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings. The configuration of the electronic throttle control device according to Embodiment 3 of the present invention is the same as that of Embodiment 1 above.
[0061]
The operation of the electronic throttle control apparatus according to Embodiment 3 of the present invention will be described with reference to the drawings.
[0062]
FIG. 10 is a flowchart showing an operation when the characteristic of the throttle opening sensor of the electronic throttle control device according to Embodiment 3 of the present invention is abnormal.
[0063]
FIG. 10 shows a processing flow for sticking the sensor output voltage to the supply voltage due to a drop in the supply voltage to the non-contact type throttle opening sensor 4 due to poor contact on the power supply side or ground side of the throttle opening sensor 4. It is a thing.
[0064]
In step 301, the microcomputer (throttle control means) 5 outputs an output voltage VTPS1 from the first throttle opening voltage detection means 53 via an A / D converter (not shown), and an A / D converter (not shown). ) To read the output voltage VTPS2 from the second throttle opening voltage detecting means 54, and the difference between the added value of the two throttle opening voltages (= VTPS1 + VTPS2) and the third predetermined voltage VC3 (for example, 5V) Absolute value Vsub = | (VTPS1 + VTPS2) −VC3 |.
[0065]
Next, in step 302, the absolute value Vsub of the difference obtained in the previous step 301 is compared with a fourth predetermined voltage VC4 (for example, 0.5V). If Vsub> VC4 is not satisfied (Vsub ≦ VC4), the step is performed. Proceed to 307, and if Vsub> VC4, proceed to the next step 303.
[0066]
Next, in step 303, Vsub> VC4 duration Tt is compared with a third predetermined time Tf3 (for example, 0.5 seconds). If Tt> Tf3, the process proceeds to the next step 304, and if Tt> Tf3 is not satisfied Goes to step 306.
[0067]
Next, in step 304, it is determined that the characteristic of the throttle opening sensor (TPS) is abnormal.
[0068]
Next, in step 305, as the retreat travel process, the power supply to the throttle actuator 3 is cut off (for example, the relay is turned off), the throttle valve 34 is returned to the retreat travel opening position, and the engine output for retreat travel is limited. .
[0069]
In step 306, feedback (F / B) control of the throttle opening position is prohibited.
[0070]
In step 307, the microcomputer (throttle control means) 5 performs feedback (F / B) control of the throttle opening position. That is, the target throttle opening position of the throttle valve 34 is calculated based on the accelerator opening signal and the engine speed signal, and the throttle opening signal is set so that the opening position of the throttle valve 34 matches the target throttle opening position. Based on the above, feedback control of the opening position of the throttle valve 34 is performed.
[0071]
Although the third predetermined voltage VC3 is a fixed value of 5V, the added value of the first and second throttle opening voltage fully closed voltage learning values VTPS1L and VTPS2L as the third predetermined voltage VC3 (VC3 = VTPSL + VTPSL) If this is used, it is possible to obtain an effect that the contact failure on the power source side and the ground side of the throttle opening sensor 4 can be detected with high accuracy.
[0072]
That is, by prohibiting the feedback control of the throttle opening position in step 306, a reset state due to a drop in the sensor supply voltage due to poor contact between the power supply side terminal and the ground side terminal of the non-contact sensor can be detected, and the sensor output voltage is supplied to the sensor. By sticking to the voltage, there is no need to press the throttle valve 34 against the fully closed stopper position by feedback control of the throttle opening position, so that a predetermined amount of air can be sucked at the time of engine start and engine startability is ensured. During engine operation, engine stall can be avoided, and the throttle valve 34 is not unnecessarily pressed against the fully closed stopper position, so that fluctuations in the throttle fully closed position due to wear of the fully closed stopper material and the throttle actuator 3 are suppressed. The reduction gear 32 is made of resin In the case of using the gear it has the effect of durability can be prevented deformation and damage of the gears due to abutment stopper is secured.
[0073]
If it is determined in step 304 that the throttle opening sensor (TPS) characteristic is abnormal, the throttle valve 34 is returned to the opening position for retreat travel so that retreat travel is performed, so that safety during retreat travel can be ensured. There is.
[0074]
【The invention's effect】
As described above, the electronic throttle control device according to the present invention prohibits the throttle opening position from being pressed against the fully closed stopper position by prohibiting the feedback control of the throttle opening position. The amount of air can be sucked in, engine startability is ensured, engine stall can be avoided during engine operation, and the throttle valve 34 is not unnecessarily pressed against the fully closed stopper position. In the case where a resin gear is used for suppressing the fluctuation of the throttle fully closed position due to the wear of the material and the reduction gear 32 of the throttle actuator 3, the gear can be prevented from being deformed or damaged due to the stopper hitting and the durability can be ensured. .
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an electronic throttle control device according to Embodiment 1 of the present invention.
2 is a diagram showing a schematic configuration of an input I / F circuit of a throttle opening sensor and an accelerator opening sensor of the electronic throttle control device according to Embodiment 1 of the present invention; FIG.
FIG. 3 is a diagram showing an internal configuration of a non-contact type throttle opening sensor of the electronic throttle control device according to Embodiment 1 of the present invention.
FIG. 4 is a diagram showing an output characteristic of a throttle opening sensor (TPS) of the electronic throttle control device according to Embodiment 1 of the present invention.
FIG. 5 is a diagram showing output characteristics of an accelerator opening sensor (APS) of the electronic throttle control device according to Embodiment 1 of the present invention;
FIG. 6 is a timing chart showing changes in the output voltage of the throttle opening sensor when the battery voltage of the electronic throttle control device according to Embodiment 1 of the present invention decreases.
FIG. 7 is a timing chart showing a change in the output voltage of the throttle opening sensor when the sensor supply voltage of the electronic throttle control device according to Embodiment 1 of the present invention is in any abnormality.
FIG. 8 is a flowchart showing an operation of the electronic throttle control device according to Embodiment 1 of the present invention when the voltage is abnormal.
FIG. 9 is a flowchart showing an operation of the electronic throttle control device according to Embodiment 2 of the present invention when the voltage is abnormal.
FIG. 10 is a flowchart showing an operation when the characteristic of the throttle opening sensor of the electronic throttle control device according to Embodiment 3 of the present invention is abnormal.
[Explanation of symbols]
1 accelerator opening sensor (APS), 2 electronic control unit (ECU), 3 throttle actuator, 4 throttle opening sensor (TPS), 5 microcomputer, 6 drive circuit, 7 battery, 8 Hall IC, 31 motor, 32 reduction gear 33 throttle shaft, 34 throttle valve.

Claims (1)

A non-contact type accelerator opening sensor that detects an operation amount of an accelerator pedal and outputs an accelerator opening signal;
A throttle actuator having a motor for driving a throttle valve for adjusting the amount of intake air into the engine;
A non-contact type throttle opening sensor that detects the opening of the throttle valve and outputs a throttle opening signal;
Battery voltage detection means for detecting the voltage of the battery;
Sensor power supply voltage detection means for detecting the sensor supply voltage;
The target throttle opening position of the throttle valve is calculated based on the accelerator opening signal and the engine speed signal, and the throttle opening position is adjusted so that the throttle valve opening position matches the target throttle opening position. Throttle control means for performing feedback control of the opening position of the throttle valve based on a signal,
The throttle control means includes
The battery voltage detected by the battery voltage detecting means is compared with a first predetermined voltage that is approximately ½ of the normal operating voltage of the battery voltage, and the battery voltage is less than the first predetermined voltage; and Continued battery voltage reduction when the engine is started, when the battery voltage is less than the first predetermined voltage, and when the engine is not started, and when the battery voltage is less than the first predetermined voltage If the time does not exceed the first predetermined time, the throttle valve opening position feedback control is prohibited,
When the battery voltage is equal to or higher than the first predetermined voltage and the sensor supply voltage detected by the sensor power supply voltage detecting means is compared with a second predetermined voltage lower than the first predetermined voltage, the sensor A sensor supply voltage drop duration that is a case where the supply voltage is less than the second predetermined voltage and the sensor supply voltage is less than the second predetermined voltage is shorter than the first predetermined time. If the predetermined time has not been exceeded, feedback control of the throttle valve opening position is prohibited ,
When the battery voltage is less than the first predetermined voltage and not at the time of engine start, and when the battery voltage drop continuation time exceeds the first predetermined time, the battery voltage is It is determined that there is an abnormality, and the throttle valve is controlled to return to the retreat travel opening position as a retreat travel process,
When the battery voltage is greater than or equal to the first predetermined voltage, and when the sensor supply voltage is less than the second predetermined voltage, and the sensor supply voltage drop duration exceeds the second predetermined time. If it is determined that the sensor supply voltage is abnormal , the electronic throttle control device controls the throttle valve to return to the retreat travel opening position as a retreat travel process .

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