JP5434711B2 - Vehicle travel control device - Google Patents

Description

  The present invention relates to a vehicle travel control device, and more particularly to a travel control device that performs auto-cruise control, and belongs to the field of vehicle automatic travel technology.

  As vehicle auto-cruise control, vehicle speed control that carries out constant speed running while maintaining the vehicle speed at the target vehicle speed, and inter-vehicle distance control that carries out follow-up running by controlling the inter-vehicle distance between the host vehicle and the preceding vehicle to the target distance, etc. In these controls, engine control and brake control are automatically performed in order to maintain the target vehicle speed or the target inter-vehicle distance.

  This auto-cruise control is also performed in a vehicle equipped with a manual transmission, but in the case of a vehicle equipped with a manual transmission, the driver may disengage the clutch during auto-cruise control and perform a gear shifting operation. In vehicle speed control, the control is usually canceled (terminated).

  However, in the inter-vehicle distance control, for example, considering the fuel efficiency and quietness, the gear position is shifted up to reduce the engine speed, or the engine brake is operated to temporarily increase the inter-vehicle distance. Since operations such as downshifting are performed relatively frequently, if the control is canceled each time, the cancellation and setting of the control are frequently repeated, and the operation becomes complicated.

  Therefore, for example, as disclosed in Patent Document 1, in the case of inter-vehicle distance control, even if the clutch is disconnected for a shift operation, the control is not canceled, the shift operation is terminated, and the clutch is connected. Sometimes it is considered to automatically resume the control. In particular, in Patent Document 1, when the clutch is connected after the shift operation and the inter-vehicle distance control is resumed, the engine output torque is controlled so as to cancel the engine brake torque, and the shock at the time of clutch connection is suppressed. Inhibiting is described.

Japanese Patent No. 3750584

  By the way, in a vehicle equipped with a manual transmission, when the clutch is disengaged for shifting operation during the inter-vehicle distance control and the transmission of power from the engine to the drive wheels is interrupted, the inter-vehicle distance control is not canceled. Since the engine control is continued in the power cut-off state, the engine speed may rapidly increase due to a rapid decrease in load, and so-called blow-up may occur. In this case, the driver feels uncomfortable, especially when the gear shift intended by the driver is a shift-up to reduce the engine speed, and to give anxiety that the driver may have failed. Also become.

  This problem occurs not only in the case of the inter-vehicle distance control but also in the vehicle speed control when the control is not canceled even if a power cut-off operation such as a clutch disengagement operation is performed.

  The present invention addresses the above-described problems during auto-cruise control in a vehicle equipped with a manual transmission. During execution of vehicle speed control or inter-vehicle distance control, the clutch is disengaged or a manual shift is performed. It is an object of the present invention to suppress the engine speed from rising when the transmission of power from the engine to the drive wheels is interrupted, such as when the machine is once shifted to the neutral position.

  In order to solve the above-described problems, a vehicle travel control apparatus according to the present invention is configured as follows.

In the first aspect of the present invention, a clutch that is connected / disconnected by the driver, a manual transmission that is operated by the driver, and at least the engine to control the vehicle speed or the inter-vehicle distance. In a vehicle travel control device provided with an auto cruise control means for performing auto cruise control to maintain a value, power for interrupting power transmission from the engine to the drive wheels during auto cruise control by the auto cruise control means When the shut-off operation is performed, the engine speed when the gear stage of the manual transmission is shifted up by one stage from the state immediately before the power shut-off operation is set to the target speed, and matches the target speed. in an engine control unit for controlling the engine speed, the engine control means, the accelerator pedal is depressed in the control of the engine speed as If it is rare, compare the engine speed according to the amount of depression and the target speed, and when the former speed is higher than the latter, reset the former speed to the target speed. Then, the engine speed is controlled .

  The invention according to claim 2 is the vehicle travel control apparatus according to claim 1, wherein the engine control means controls the engine speed and cuts off fuel supply to the engine. It is characterized by performing control and feedback control of the engine speed by controlling the throttle opening.

  The invention according to claim 3 is the vehicle travel control device according to claim 2, wherein the engine control means performs the fuel cut control when the engine speed substantially matches the target speed. It is characterized by terminating.

  According to a fourth aspect of the present invention, in the vehicle travel control apparatus according to the second or third aspect of the present invention, the engine control means moves to the travel position of the manual transmission after the power cut-off operation. The feedback control is performed until the power connection operation by the shift operation and the clutch connection operation is performed.

The invention according to claim 5 is the vehicle travel control apparatus according to any one of claims 1 to 4, wherein the engine control means shifts the gear stage of the manual transmission by one stage. when setting the engine speed obtained while up to the target rotational speed, and sets so as to gradually shift to the engine speed.

Furthermore, the invention according to claim 6 is the vehicle shift control device according to any one of claims 1 to 5 , wherein a shift operation detection for detecting a shift operation of the manual transmission by a driver is performed. And the engine control means shifts the target speed of the engine speed by one step when the shift means for shifting down the shift speed is detected by the detection means after the power cut-off operation. The engine speed is reset to that when the engine is down, and the engine speed is controlled to match the target speed.

According to a seventh aspect of the present invention, in the vehicle travel control device according to any one of the first to sixth aspects, the auto-cruise control means controls the vehicle speed to a target value. And inter-vehicle distance control for controlling the inter-vehicle distance to a target value, and the engine control means performs the control only when the power shut-off operation is performed during inter-vehicle distance control, and The auto-cruise control means cancels the auto-cruise control when the power cut-off operation is performed during the vehicle speed control.

  With the above configuration, according to the invention of each claim of the present application, the following effects can be obtained.

  First, according to the first aspect of the invention, during auto-cruise control in which the vehicle speed or the inter-vehicle distance is controlled to a target value by the auto-cruise control means, such as a clutch disengagement operation or a shift operation to the neutral position of the transmission. When a power cut-off operation that cuts off the transmission of power from the engine to the drive wheel is performed, the engine control means shifts the gear stage of the manual transmission one step up from the state immediately before the power cut-off operation. The engine speed is controlled with the engine speed as the target speed. Therefore, even if the engine load is drastically reduced due to the power cut-off operation, the engine speed is prevented from being increased, thereby preventing the driver from feeling uncomfortable or uneasy.

If the operation of the manual transmission after the power cut-off operation is an operation for shifting up the shift speed by one step, the engine speed is reduced in advance to the speed at the operated shift speed. After the operation, when the clutch is connected to be in a power transmission state, the clutch is connected in a so-called rotationally aligned state. Therefore, the clutch is smoothly connected without generating a shock. Further, when the accelerator pedal is depressed during the control of the engine rotation speed by the engine rotation speed control means, the engine rotation speed corresponding to the depression amount and the target rotation speed are controlled to the higher rotation speed. Therefore, for example, when the shift operation during power cut-off due to clutch disengagement or the like is a shift-down operation, and the driver steps on the accelerator pedal to adjust the rotation, the engine speed is set in advance to the speed after the shift-down. Since they are close to each other, the clutch is smoothly connected after the speed change operation.

  According to the invention described in claim 2, when the engine control means reduces the engine speed to the speed when the shift speed of the manual transmission is shifted up by one stage, the throttle opening degree control is performed. In addition, since the fuel cut control is performed, the engine speed can be rapidly reduced to the target speed as compared with the case where the speed is reduced only by controlling the throttle opening.

  Therefore, when the gear shift up operation is performed, after the power cut-off operation, even if the shift up operation and the clutch connection operation are performed in a short time, the engine speed is the target speed when the clutch is connected. Thus, the occurrence of a shock when the clutch is engaged is more reliably suppressed.

  According to the third aspect of the present invention, the fuel cut control for controlling the engine speed to the target speed ends when the engine speed substantially matches the target speed. Even if the clutch is connected to the vehicle and the auto-cruise control is resumed, the power necessary for the auto-cruise control is immediately output from the engine, and the auto-cruise control is resumed without delay.

  According to the fourth aspect of the present invention, the feedback control for controlling the engine speed to the target speed is performed after the power disconnection operation such as the clutch disengagement operation and the power connection operation such as the clutch connection operation. Since it is performed until it is performed, the engine speed can be accurately controlled to the target speed until the clutch is engaged. Therefore, when the shift operation of the manual transmission is an operation for shifting up the shift stage by one stage, the clutch is more smoothly connected.

According to the fifth aspect of the present invention, when the target engine speed of the engine speed is set to the speed obtained when the manual transmission gear stage is shifted up by one stage, the engine speed is gradually shifted to that speed. Therefore, a rapid change in the engine speed after the power cut-off operation is prevented, and the uncomfortable feeling given to the driver is suppressed. In particular, when the fuel cut control is performed, the engine speed can be quickly matched with the target engine speed while suppressing a rapid decrease in the engine engine speed.

According to the sixth aspect of the present invention, after the power cut-off operation, when the operation for shifting down the shift stage of the manual transmission is detected by the shift operation detecting means, the target engine speed is changed. Since the engine speed is controlled to match the reset target speed, the shift-down operation is completed and the clutch is connected. When the engine speed is set, the engine speed is increased in advance to the speed after the downshift or to a speed close to the speed, and the clutch is smoothly connected in a state where the clutch is rotated.

According to the seventh aspect of the present invention, when auto-cruise control can be selected between vehicle speed control for controlling the vehicle speed to the target value and inter-vehicle distance control for controlling the inter-vehicle distance to the target value. Since the engine speed is controlled by the engine control means only when the inter-vehicle distance control is executed, the above-described effects of the engine speed control can be obtained during a shift operation during the inter-vehicle distance control that is relatively frequent. As well as being realized, during vehicle speed control where the frequency of shifting operations is relatively low, auto-cruise control itself is canceled due to clutch disengagement, etc., and automatic travel control suitable for both inter-vehicle distance control and vehicle speed control is possible Become.

It is a control system figure concerning an embodiment of the present invention. It is a flowchart which shows the operation | movement of auto-cruise control. It is a time chart. It is a flowchart which shows the operation | movement of the auto cruise control which concerns on other embodiment. It is a time chart.

  Hereinafter, embodiments of the present invention will be described.

  First, the configuration of the vehicle according to the present embodiment will be described with reference to FIG. 1. The vehicle 1 includes an engine 2, a clutch 3, a manual transmission (hereinafter referred to as “transmission”) 4, and a differential device 5. The output of the engine 1 is transmitted to the left and right drive wheels 7 and 7 via the clutch 3, the transmission 4, the differential 5 and the left and right axles 6 and 6. The front and rear wheels are provided with brake devices 8.

  Further, as operation members operated by a driver, an accelerator pedal 11 for controlling the output of the engine 2, a brake pedal 12 for operating the brake devices 8 ... 8, a clutch pedal 13 for connecting and disconnecting the clutch 3, A shift lever 14 for switching the gear position of the transmission 4 is provided.

  The above-described configuration of the vehicle 1 is a well-known configuration, and is not limited to the front engine / front drive vehicle as shown in the figure, and the same applies to the front engine / rear drive vehicle and the like.

  Furthermore, the vehicle 1 according to this embodiment has a travel control device capable of auto-cruise control, a control unit 20 constituting the device, a set switch 21 for starting auto-cruise control, and canceling the control. And a cancel switch 22 is provided, and signals from these switches 21 and 22 are input to the control unit 20.

  The control unit 20 includes an inter-vehicle distance sensor 23 such as a laser radar that detects the inter-vehicle distance from the preceding vehicle, an engine speed sensor 24 that detects the rotational speed of the engine 2, and an output rotational speed of the transmission 4. The vehicle speed sensor 25 for detecting the vehicle speed from the above, the accelerator sensor 26 for detecting the depression amount of the accelerator pedal 11, the brake switch 27 for detecting the depression operation of the brake pedal 12, and the clutch for detecting the depression operation of the clutch pedal 13 A switch 28 is provided, and signals from these sensors and switches 23 to 28 are input to the control unit 20.

  The control unit 20 controls the output of the engine 2 and the operation of the brake device 8 based on the signals from the sensors and the switches 23 to 28 when the set switch 21 for auto cruise control is turned on. Thus, auto-cruise control such as vehicle speed control for maintaining the vehicle speed at the set value and inter-vehicle distance control for maintaining the inter-vehicle distance with the preceding vehicle at the set value is performed. In this embodiment, as the auto-cruise control, both the vehicle speed control and the inter-vehicle distance control can be selectively executed.

  Next, auto-cruise control by the control unit 20, particularly control when the driver performs the disengagement operation of the clutch 3 during the auto-cruise control, will be described with reference to the flowchart of FIG. 2 and the time chart of FIG. To do.

  First, in step S1 of the flowchart, it is determined whether or not auto-cruise control is currently being executed. If the control is being executed, then in step S2, a signal from the clutch switch 28 is sent to the clutch pedal 13. Whether or not the clutch 3 has been turned off by depressing, or whether or not the shift stage of the transmission 4 has been switched to the neutral stage, that is, the power from the engine 2 to the drive wheels 7 and 7 It is determined whether or not the transmission is interrupted. When the clutch 3 is not disengaged and the speed of the transmission 4 is the travel speed and the power from the engine 2 is transmitted to the drive wheels 7 and 7, the currently executed auto Continue cruise control.

  On the other hand, when the clutch 3 is disengaged and the signal from the clutch switch 27 is turned ON, or the transmission speed is switched to the neutral speed and the transmission of power from the engine 2 to the drive wheels 7 and 7 is interrupted. Next, in step S3, it is determined whether or not the auto cruise control currently being executed is the inter-vehicle distance control. If it is not the inter-vehicle distance control, that is, if it is the vehicle speed control, the control is terminated in step S4, and the auto-cruise control itself is canceled.

  On the other hand, if the currently executed control is the inter-vehicle distance control, in step S5, the inter-vehicle distance control is temporarily interrupted while maintaining the state at that time, and then the engine speed is reduced in step S6 and the subsequent steps. The engine is controlled when the power is cut off, including feedback control.

  That is, first, in step S6, based on the signals from the engine speed sensor 24 and the vehicle speed sensor 25, the gear position of the transmission 4 immediately before the power cut-off operation is detected, and if the gear position is the highest speed step, In S7, the engine speed at the highest speed, that is, the engine speed at that time is set as the target speed of the feedback control as it is.

  On the other hand, when the gear position of the transmission 4 immediately before the power cut-off operation is not the highest speed step, for example, as shown in FIG. In the case where the speed is 4th speed, in step S8, the engine speed when the speed is shifted up by one speed from the speed immediately before the power cut-off operation is calculated as follows: the gear ratio of the speed after the speed up and the vehicle speed at that time And the rotational speed is set to the target rotational speed of the feedback control.

  If the shift stage immediately before the power shut-off operation is not the highest speed stage, a control signal is output so as to stop fuel injection from the fuel injection valve 2a provided in the engine 2 in step S9. Start fuel cut control without supplying fuel to the chamber.

  In either case, feedback control is then started in step S10 so that the engine speed matches the target speed set as described above. This feedback control is performed by outputting a control signal to the throttle actuator 29 so as to open and close the throttle valve 2a in accordance with the deviation between the actual rotational speed detected by the engine rotational speed sensor 24 and the target rotational speed.

  As a result, the engine speed is controlled so as to match the target speed. However, if the gear position immediately before the power cut-off operation is not the highest speed, the engine speed when the gear position is shifted up by one step. Is set as the target engine speed, and the engine speed is reduced by this feedback control.

  In this case, in this embodiment, as indicated by the symbol a in FIG. 3, the target rotational speed is set so as to gradually decrease to the rotational speed when the shift stage is shifted up by one stage. The number also gradually decreases to the target rotational speed, and the driver does not feel uncomfortable due to the rapid decrease. At this time, since the fuel cut control is performed, the actual rotational speed follows the target rotational speed with good responsiveness, and the decrease in the actual rotational speed is not delayed.

  The feedback control that lowers the engine speed suppresses the engine speed from being increased due to the clutch 3 being disconnected. In particular, the fuel cut control is used together to reliably prevent the engine speed from rising. Will be. Also, when it is determined in step S6 that the gear position immediately before the power cut-off operation is the highest speed stage, feedback control is performed with the engine speed at that time as the target engine speed. Blowing up is suppressed.

  Thereafter, in step S11, whether or not the transmission 4 is switched to the traveling stage and the signal from the clutch switch 28 is switched to OFF, that is, the power from the engine 2 is transmitted to the drive wheels 7 and 7. It is determined whether or not the state has been switched to a state in which it is switched to, and if not yet switched to this power transmission state, whether or not the accelerator pedal 13 has been depressed based on the signal from the accelerator sensor 26 in step S12. Determine.

  As a result of these determinations, when the power transmission state is not switched and the accelerator pedal 11 is not depressed, the feedback control is continued, and the gear stage immediately before the power shutoff operation is not the highest speed stage. Continues the control to reduce the engine speed. In step S13, it is determined whether or not the engine speed has decreased until it substantially matches the target rotational speed. If it is determined that the engine speed has decreased, fuel injection is resumed in the fuel injection valve 2a in step S14. Thus, the control signal is output to terminate the fuel cut control, and thereafter, only the feedback control in step S10 is executed.

  As a result, when the gear position immediately before the power shut-off operation is not the highest speed, the engine speed is controlled to the speed when the gear position is shifted up by one stage, as indicated by reference numeral b in FIG. . After that, if it is determined in step S11 that the power transmission state has been switched, the feedback control is terminated in step S15, and the inter-vehicle distance control is restarted in step S16.

  At this time, since the engine speed is controlled to the speed when the gear stage is shifted up by one stage from the speed immediately before the power shut-off operation, the gear stage of the transmission 4 is shifted up by one stage while the power is shut off. If the operation is performed, the rotation alignment is already completed when the clutch 3 is connected, and the clutch 3 is smoothly connected without causing a shock.

  On the other hand, if it is determined in step S12 that the accelerator pedal 11 has been depressed before switching to the power transmission state, then in step S17, the engine speed corresponding to the depression amount of the accelerator pedal 11, In other words, it is determined whether or not the driver's required rotational speed is higher than the target rotational speed. If it is higher, in step 18, the required rotational speed is reset to the target rotational speed. If the fuel cut control is still continued, the control is terminated in step S14, and the feedback control in step S10 is performed so as to match the reset target rotational speed.

  In this case, as indicated by reference symbol c in FIG. 3, the engine speed that once started to decrease or decreased to the initial target speed increases from the time when the accelerator pedal 11 is depressed. 11 is presumed to be accompanied by shifting down the gear position while the power is cut off for acceleration. Therefore, if the gear position is shifted down when the power transmission state is established, the clutch 3 is The clutch 3 is connected in a state where the rotation is almost matched, and the clutch 3 is smoothly connected.

  When the shift operation during the power cut-off is shifted down but the accelerator pedal 11 is not depressed, as shown by a symbol d in FIG. The rotational speed when shifted up or the rotational speed corresponding to the highest speed stage is increased to the rotational speed corresponding to the shift stage shifted down.

  Next, another embodiment of the present invention will be described.

  In this embodiment, in addition to the configuration of the embodiment, a shift position sensor 30 for detecting the shift operation position of the change lever 14 by the driver is provided as shown by a chain line in FIG. The signal is input to the control unit 20.

  The auto-cruise control in this embodiment is almost the same as in the above-described embodiment. As shown in the flowchart in FIG. 4, the clutch 3 is disconnected during the inter-vehicle distance control in steps S1 ′ to S10 ′ as in the above-described embodiment. When the transmission of power from the engine 2 to the drive wheels 7 and 7 is interrupted, and the gear stage immediately before the shut-off operation is not the highest speed, the engine speed when the gear stage is shifted up by one stage is set. When the highest speed stage is set as the target rotational speed, the engine rotational speed at that time is set to the target rotational speed, and then feedback control is performed to match the engine rotational speed with the target rotational speed. Further, when the shift stage immediately before the power shut-off operation is not the highest speed stage, fuel cut control is also started.

  Then, in step S11 ′, it is determined whether or not the state has shifted to the power transmission state, for example, the clutch 3 is connected. If the shift has not yet been performed, in this embodiment, the shift position sensor 30 is determined in step S12 ′. Based on the signal from the above, it is determined whether or not an operation for shifting down the gear position of the transmission 4 has been performed.

  When the shift-down operation is not performed, the feedback control is continued, and when the shift stage immediately before the power cut-off operation is not the highest speed stage, the control for reducing the engine speed is continued together with the fuel cut control. At the same time, if it is determined in step S13 ′ that the engine speed substantially coincides with the target speed, the fuel cut control is terminated in step S14 ′. Further, when the gear position immediately before the power cut-off operation is the highest speed stage, feedback control is performed so as to maintain the engine speed.

  Therefore, in this embodiment as well, the increase in the engine speed immediately after the power cut-off operation is suppressed, and the gear stage immediately before the power cut-off operation is not the highest speed stage, and the gear stage is shifted up by one stage during the power cut-off. When the operation is performed, the clutch 3 is smoothly connected in a state where the rotation is aligned, and the clutch 3 is smoothly connected. Then, when the state is shifted to the power transmission state due to the connection of the clutch 3 or the like, the feedback control is ended in step S15 'and the inter-vehicle distance control is restarted in step S16'.

  On the other hand, if it is determined in step S12 ′ that an operation for shifting down the gear position is performed during power interruption, then in step S17 ′, as shown by symbol e in FIG. When the engine speed is shifted down to the detected gear position from the previous gear position, the engine speed is reset to the target speed for feedback control. If fuel cut control is being performed, the control is terminated in step S14 '. Then, feedback control is performed so as to match the reset target rotational speed.

  As a result, as indicated by the symbol f in FIG. 5, the engine speed increases. After that, if it is determined in step S11 ′ that the transition to the power transmission state is made, the feedback control is terminated in step S15 ′. In step S16 ′, the inter-vehicle distance control is resumed. At this time, since the engine speed is controlled to the speed corresponding to the shift-shifted gear position, the clutch 3 is rotated. As in the case of upshifting, the connection is made smoothly without causing a shock.

  In addition, you may implement control when the shift down operation is detected by the shift position sensor 30 in this embodiment in the said embodiment which shows a flowchart and a time chart in FIG.

  In both the embodiments, the auto-cruise control itself is canceled when an operation such as clutch disconnection is performed during the vehicle speed control. However, even during the vehicle speed control, the inter-vehicle distance control is being performed. You may perform control similar to control.

  As described above, according to the present invention, auto-cruise control in a vehicle equipped with a manual transmission can be performed satisfactorily. Therefore, the present invention is preferably used in the manufacturing industry of this type of vehicle. There is a possibility.

1 vehicle 2 engine 3 clutch 4 manual transmission 20 control unit (auto cruise control means, engine control means)

Claims (7)

A clutch that is connected / disconnected by the driver, a manual transmission that is operated by the driver, and an auto-cruise control means that performs auto-cruise control that controls at least the engine and maintains the vehicle speed or the inter-vehicle distance at a target value. When the power cut-off operation for cutting off the power transmission from the engine to the drive wheels is performed during the auto-cruise control by the auto-cruise control means, the power cut-off operation Provided with an engine control means for setting the engine speed when the manual transmission is shifted up one stage from the state immediately before the target speed and controlling the engine speed so as to coincide with the target speed. When the accelerator pedal is depressed during the control of the engine speed, the engine control means responds to the depression amount. Characterized in that by comparing the engine speed and the target speed, the former speed when higher than the latter speed, the rotational speed of the former to reconfigure to the target rotational speed for controlling engine speed A vehicle travel control device.   The engine control means performs the engine speed control by fuel cut control for cutting off fuel supply to the engine and engine speed feedback control by throttle opening control. The vehicle travel control device according to claim 1.   3. The vehicle travel control device according to claim 2, wherein the engine control unit ends the fuel cut control when the engine speed substantially coincides with a target speed. 4.   The engine control means performs the feedback control after the power cut-off operation until a power connection operation by a shift operation to the travel position of the manual transmission and a clutch connection operation is performed. The vehicle travel control device according to claim 2 or claim 3. Said engine control means, wherein the gear position of the manual transmission the engine speed obtained while stage shift-up when setting the target rotational speed is set so as to gradually shift to the engine speed The travel control device for a vehicle according to any one of claims 1 to 4. A shift operation detecting means for detecting a shift operation of the manual transmission performed by a driver, and the engine control means detects a shift operation for shifting down a gear position by the detecting means after the power shut-off operation; In addition, the target engine speed of the engine speed is reset to the engine speed when the gear position is shifted down by one step, and the engine speed is controlled to match the target speed. The travel control device for a vehicle according to any one of claims 1 to 5. The auto-cruise control means can selectively execute vehicle speed control for controlling the vehicle speed to a target value and inter-vehicle distance control for controlling the inter-vehicle distance to a target value, and the engine control means can perform the vehicle control during the inter-vehicle distance control. The control is performed only when a power cut-off operation is performed, and the auto-cruise control means cancels the auto-cruise control when the power cut-off operation is performed during vehicle speed control. The travel control device for a vehicle according to any one of claims 1 to 6.

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