JP2016159835A - Reaction force output device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reaction force output device that can suppress reaction force from being excessively output.SOLUTION: In a reaction force output device that outputs to an operator force in the opposite direction of an operation direction, a driving portion outputs to an operator to be operated by a person force in the opposite direction of the operation direction by driving a driving member, and a control portion determines on the basis of an input value control amounts to be given to the driving portion, and performs friction-suppression control so that the control amounts are determined to be smaller relative to the input value when set conditions indicating a situation where overshoot of the force in the opposite direction of the operation direction is likely to occur is satisfied than when the set conditions are not satisfied.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a reaction force output device.

  An accelerator pedal device that outputs a force (reaction force) in the opposite direction to the force that depresses the accelerator pedal (stepping force) to the accelerator pedal, for example, in order to suppress unintended sudden acceleration when the vehicle starts or travels. It is known (see, for example, Patent Document 1).

  The accelerator pedal device described in Patent Document 1 includes a housing that pivotally supports the base end of a pedal arm, a return spring for returning the pedal arm to an initial position, a motor for creating a reaction force, A lever for transmitting the rotation of the motor to the pedal arm is incorporated. In this accelerator pedal device, the motor is controlled by the control device to an output corresponding to the depression state of the accelerator pedal, and the output is applied to the pedal arm through the transmission lever.

  Such a reaction force output device not only suppresses sudden acceleration, but also adopts a structure in which the connection between the accelerator pedal and the throttle valve is omitted (so-called drive-by-wire), the natural pedaling comfort of the accelerator pedal ( It is also used to give the driver an accelerator feeling).

JP 2010-111379 A

  However, in the conventional reaction force output device, the reaction force output to the operation element may be felt greatly due to the friction torque of the motor. As a result, for example, when applied to an accelerator pedal device, the accelerator feeling may deteriorate.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a reaction force output device that can suppress an excessive output of reaction force.

The reaction force output device of the present invention employs the following configuration.
(1) By driving the driving member, a driving unit that outputs a force in a direction opposite to the operation direction with respect to an operator operated by a person, and a control amount to be given to the driving unit based on an input value are determined. A control unit that satisfies a setting condition indicating that a force overshoot in a direction opposite to the operation direction is likely to occur, the control amount compared to a case where the setting condition is not satisfied. And a control unit that performs friction suppression control that determines the input value to be smaller than the input value.
According to such a configuration, the reaction force output device is relative to the input value as compared with the control amount when the setting condition is not satisfied when the setting condition indicating that reaction force overshoot is likely to occur. By providing a small control amount and energizing the drive unit with a current based on a control amount that is relatively small with respect to the input value, it is possible to suppress an excessive output of the reaction force. As a result, the reaction force output device can improve the accelerator feeling when the driver steps on the accelerator pedal, for example.

(2) The control unit may gradually increase the control amount until a predetermined period elapses after the setting condition is satisfied.
According to the structure which concerns, the reaction force output device can suppress gradually that reaction force is output excessively at the time of operation start. As a result, the reaction force output device can further improve the accelerator feeling when the driver depresses the accelerator pedal, for example.

(3) The drive unit may be a motor, and the setting condition may include that the rotational speed of the motor exceeds a threshold value and that the change in the rotational speed of the motor is large.
According to such a configuration, the reaction force output device can determine that the reaction force is likely to overshoot when the rotation speed of the motor exceeds a threshold value and the change in the rotation speed of the motor is large. Based on the determination result, the friction suppression control can be performed. As a result, the reaction force output device can improve the accelerator feeling when the driver depresses the accelerator pedal, for example.

(4) The drive unit may be a motor, and the setting condition may include that the rotational speed of the motor is near zero.
According to this configuration, the reaction force output device can determine that reaction force overshoot is likely to occur when the rotational speed of the motor is near zero, and performs friction suppression control based on the determination result. Can do. As a result, the reaction force output device can improve the accelerator feeling when the driver depresses the accelerator pedal, for example.

(5) The setting condition includes that the rotational speed of the motor exceeds a threshold value, and a change in the rotational speed of the motor exceeds a second threshold value determined according to the rotational speed of the motor. May be.
According to such a configuration, the reaction force output device has a reaction force when the rotational speed of the motor exceeds the threshold value and the change in the rotational speed of the motor exceeds the second threshold value determined according to the rotational speed of the motor. It can be determined that force overshoot is likely to occur, and friction suppression control can be performed based on the determination result. As a result, the reaction force output device can improve the accelerator feeling when the driver depresses the accelerator pedal, for example.

  ADVANTAGE OF THE INVENTION According to this invention, the reaction force output device which can suppress the reaction force output excessively can be provided.

It is a figure showing an example of the appearance composition of accelerator pedal device 1 provided with reaction force output device 10 concerning one embodiment. It is a figure showing an example of an internal structure of reaction force output device 10 concerning one embodiment. It is a figure showing an example of functional composition centering on a control circuit of reaction force output device 10 concerning one embodiment. It is the figure which compared the influence of friction torque with the effect by control of the microcomputer 56. FIG. It is a map which shows an example of the control area | region which performs friction suppression control. It is a flowchart which shows the flow of the process performed by the control circuit of the reaction force output device 10 which concerns on one Embodiment.

  Hereinafter, embodiments of a reaction force output device of the present invention will be described with reference to the drawings. A reaction force output device according to an embodiment outputs, for example, a force (reaction force) opposite to a stepping force (stepping force) to an operator such as an accelerator pedal provided for instructing acceleration of the vehicle. Device. By using the reaction force output device, it is possible to improve the accelerator feeling, to transmit the accelerator work that saves fuel consumption, and to perform various safety controls. Safety control includes control that outputs a relatively large reaction force in order to suppress excessive acceleration before a curve, in an urban area, a school zone, or the like. In addition, when the accelerator pedal is simply operated exceeding the reference, it may be determined that the operation is erroneous and control to output a large reaction force may be performed. In addition, the operation element that is the reaction force output target in the present embodiment is not limited to the accelerator pedal, and may be a brake pedal, a steering wheel, an operation device of a game machine, or the like.

Drawing 1 is a figure showing an example of the appearance composition of accelerator pedal device 1 provided with reaction force output device 10 concerning one embodiment.
The accelerator pedal device 1 includes a pedal body unit 2 installed in front of the driver's seat and a reaction force output device 10 installed above the pedal body unit 2.

  The pedal body unit 2 is provided on a holding base 2a attached to the vehicle body, a pedal arm 4 whose base end is rotatably supported by a support shaft 2b provided on the holding base 2a, and a distal end portion of the pedal arm 4. The holding base 2a is provided with a return spring (not shown) that constantly urges the pedal arm 4 to the initial position.

  A cable (not shown) for operating the opening of a throttle valve (not shown) of the internal combustion engine (engine) is connected to the pedal arm 4 in accordance with the operation amount (rotation angle) of the pedal arm 4. However, when the internal combustion engine employs an electronically controlled throttle, a rotation sensor for detecting the rotation angle of the pedal arm 4 is provided in the pedal body unit 2, and the throttle valve is detected based on the detection signal of the rotation sensor. The opening degree may be controlled. Further, a reaction force transmission lever 8 extending in a direction substantially opposite to the extending direction of the pedal arm 4 is integrally connected to the vicinity of the base end of the pedal arm 4.

  Further, the distal end portion of the output lever 12 that is a driving member of the reaction force output device 10 and the distal end portion of the reaction force transmission lever 8 can be brought into contact with each other. The turning force of the output lever 12 that is a drive member of the reaction force output device 10 is output to the pedal arm 4 via the reaction force transmission lever 8. In this way, the reaction force output device 10 outputs a reaction force in the direction opposite to the direction of the pedaling force to the operator.

  FIG. 2 is a diagram illustrating an example of the internal structure of the reaction force output device 10 according to an embodiment. In FIG. 2, the cover of the upper surface of the housing member 14 is removed, and the internal state of the housing member 14 (reaction force output device 10) is shown. The reaction force output device 10 according to the present embodiment includes a motor 20 that is a drive source for creating a reaction force, a reaction force output shaft 16 that is pivotally supported by the housing member 14, a gear reduction mechanism 30, and the like. And a circuit board 50. The gear reduction mechanism 30 decelerates the rotation of the rotor of the motor 20 and increases the torque T output from the motor 20 side, and increases the torque T by deflecting from the motor rotation shaft 22 direction to the reaction force output shaft 16 direction. T is transmitted to the output lever 12. One end portion in the reaction force output shaft direction protrudes outward from the side surface of the housing member 14, and the output lever 12 is integrally connected to the protruding end portion.

  The rotation of the rotor of the motor 20 is controlled by a control circuit mounted on the circuit board 50. Connected to the circuit board 50 is a CAN (Controller Area Network) cable (not shown) for transmitting and receiving signals between a host ECU (Electronic Control Unit) described later and a control circuit. The circuit board 50 and the motor 20 are connected via a cable (not shown), and the rotation of the rotor of the motor 20 is controlled based on a control signal sent from the circuit board 50. In addition, a small hole, a slit, or the like is provided in the housing that covers the rotor of the motor 20, and a Hall IC (Integrated Circuit) is fitted into the small hole, the slit, or the like. The Hall IC detects the magnetic flux intensity that passes through a small hole, a slit, or the like, and outputs a pulsed voltage corresponding to the detected magnetic flux intensity. The magnetic flux intensity detected by the Hall IC changes according to the rotation of the rotor in the motor 20. For this reason, the reaction force output device 10 can detect the rotation amount of the rotor (for example, the rotation speed n [rpm]) based on the output voltage of the Hall IC.

  FIG. 3 is a diagram illustrating an example of a functional configuration centering on a control circuit of the reaction force output device 10 according to the embodiment. In FIG. 3, the reaction force output device 10 includes a CAN control circuit 54 that performs CAN communication between the motor 20 and the host ECU 70, a microcontroller (microcomputer) 56, a motor driver IC 58, a power FET (Field Effect Transistor). ) 60, Hall IC 64U, 64V, 64W, Hall IC 64, and current detection sensor 66. In the following description, the Hall ICs 64U, 64V, and 64W are collectively referred to as the Hall IC 64 unless otherwise distinguished.

  For example, the host ECU 70 controls the driving of the engine 72 by controlling the opening degree of the throttle valve in accordance with the operation amount of the pedal arm 4. In the engine 72, a crankshaft as an output shaft is connected to an axle, and outputs a driving force for driving the vehicle. The travel drive unit may have a configuration in which a travel motor is added to the engine 72, or may have a configuration in which the travel drive force is output only by the travel motor without the engine 72.

  The microcomputer 56 performs CAN communication with the host ECU 70 via the CAN control circuit 54. The microcomputer 56 receives a reaction force set value P, which is a reference for the magnitude of the reaction force generated by the reaction force output device 10, from the host ECU 70. The reaction force set value P is an example of “input value”. For example, the reaction force set value P may be determined so as to increase according to the vehicle speed of the vehicle on which the reaction force output device 10 is mounted, or in order to suppress a sudden accelerator operation in order to improve fuel efficiency. It may be determined. Further, the reaction force setting value P may be determined so as to increase as the distance between the vehicle on which the reaction force output device 10 is mounted and the preceding vehicle becomes shorter. The inter-vehicle distance is acquired by, for example, a millimeter wave radar or a sound wave sensor installed at the front portion of the vehicle, a stereo camera device installed at the top of the windshield, or the like. In addition, communication with the vehicle ahead (vehicle-to-vehicle communication), communication with external information providing communication devices on the road and in the vicinity (road-to-vehicle communication), or map information and road information provided from the in-vehicle car navigation (for example, The reaction force set value P may be set from a set point such as a destination, the presence of a stopped vehicle ahead, a distance from a sharp curve, a frequent accident point, and the like. For the application of the present invention, there is no particular limitation on the method for determining the reaction force set value P.

  The microcomputer 56 determines the current command value I as a control amount to be given to the motor driver IC 58 based on the reaction force set value P. At this time, the microcomputer 56 determines the current command value I based on a relational expression indicating the relationship between the current command value I and the reaction force set value P, for example. The motor driver IC 58 determines a pulse width, a duty ratio, and the like at the time of PWM control based on the current command value I, controls a current to be supplied to the power FET 60, and rotates the motor 20.

  The power FET 60 includes U-phase, V-phase, and W-phase power FETs 60U, 60V, and 60W, and each power FET is connected to a coil of a corresponding phase of the motor 20, respectively. The motor driver IC 58 cyclically turns on / off each phase power FET to generate a magnetic field in each phase coil, and rotates the rotor of the motor 20.

  The microcomputer 56 is connected to a current detection sensor 66 for detecting a current supplied to the motor 20 and a motor driver IC 58. The microcomputer 56 receives a signal indicating the current detected by the current detection sensor 66. In addition to the microcomputer 56, three Hall ICs 64U, 64V, 64W are connected to the input terminal of the motor driver IC 58, and the motor driver IC 58 accepts a change in voltage output from each of the Hall ICs 64U, 64V, 64W. The motor driver IC 58 outputs a signal indicating the rotational speed n of the motor 20 to the microcomputer 56 based on the input from the Hall ICs 64U, 64V, 64W. Thereby, the microcomputer 56 detects the rotation speed n of the motor 20. The microcomputer 56 determines a current command value I to be given to the motor driver IC 58 based on the detected rotation speed n of the motor 20.

  FIG. 4 is a diagram comparing the effect of friction torque with the effect of control by the microcomputer 56. In the example of FIG. 4, the graphs G1 and G3 show the current command value I [A] given to the motor driver IC 58 for the time t [s], and the graphs G2 and G4 show the time t [s]. The torque T [Nm] output by the reaction force output device 10 is shown.

  As a result of giving the current command value I in the form shown in the graph G1 to the motor driver IC 58, the torque T output by the reaction force output device 10 shows a change as shown in the graph G2, for example. When a current command value I determined based on the reaction force set value P is directly applied to the motor driver IC 58 as shown in a region A in the graph G1, when a pedaling force is started to be applied to the pedal body 6 by the driver. The torque T output as a reaction force may increase due to the friction torque of the motor 20. When the driver starts to apply the pedaling force to the pedal body 6, for example, when the vehicle on which the reaction force output device 10 is mounted starts from a stopped state, the driver removes his / her foot from the pedal body 6 and inertia For example, when the pedal body 6 is depressed from the running state and accelerated.

  As a result, the reaction force output device 10 may generate a reaction force that exceeds the reaction force setting value P that is initially assumed (when an overshoot occurs). The overshoot occurs more prominently as the gear ratio in the gear reduction mechanism 30 and the amount of change in the rotation speed n of the motor 20 are larger, and is particularly likely to occur when the motor 20 transitions from the stop state to the drive state. .

  Accordingly, the microcomputer 56 performs the following process when the setting condition indicating that the overshoot is likely to occur is satisfied. When the detected rotation speed n is 0 (hereinafter, when the motor is stopped), and when the change amount Δn of the rotation speed n is larger than a threshold value determined based on the rotation speed n, the microcomputer 56 notifies the motor driver IC 58. The given current command value I is determined to be smaller than the current command value I when the set condition is not satisfied. That is, if the current command value determined when the setting condition is not satisfied with respect to the reaction force set value P is Im, the microcomputer 56 sets the current against the same reaction force set value P when the setting condition is satisfied. The command value is determined to be Is smaller than Im. In consideration of sensor errors and the like, when the motor is stopped, it may be defined as “when the rotation speed n is less than the minute rotation speed n *”, that is, “when it is near zero”. Hereinafter, such control is referred to as “friction suppression control”. Further, the control for determining the current command value I to be given to the motor driver IC 58 as the current command value Im determined when the setting condition is not satisfied with respect to the reaction force setting value P without performing the friction suppression control is “normal”. This is referred to as “control”.

  As shown in the graph G3 of FIG. 4, the current command value Is rises from a relatively low current, such as 0 [A], rises gradually (eg, linearly), and when a predetermined time τ elapses, It is determined so as to coincide with the current command value Im when the set condition is not satisfied. Further, the current command value Is is not determined in the manner as shown in FIG. 4 but may be set in a stepped shape (step shape) or set based on a nonlinear function such as a logarithmic function or an exponential function. Also good. The predetermined time τ is an example of a “predetermined period”. The predetermined time τ is determined based on results obtained in advance by experiments or simulations. The predetermined time τ is set as a longer period when the friction torque is large due to, for example, the specification of the motor 20.

  As shown in the graph G4 in FIG. 4, when the friction suppression control is performed, the occurrence of overshoot is suppressed when the driver starts to apply the pedaling force to the pedal body 6. As a result, the reaction force output device 10 can suppress an excessive output of the reaction force in a scene where overshoot is likely to occur, such as when the operation of the pedal body 6 starts.

The microcomputer 56 determines whether or not to perform the friction suppression control according to the rotational speed n of the motor 20 detected based on the input from the motor driver IC 58. Hereinafter, this process will be described with reference to FIG.
FIG. 5 is a map illustrating an example of a control region in which friction suppression control is performed. In the figure, Δn indicates the amount of change in the rotational speed n. Δn represents, for example, a difference between two rotation speeds n among a plurality of rotation speeds n detected at predetermined detection intervals.

The microcomputer 56 performs friction suppression control in a region A (region overlapping the vertical axis) and a region B shown in the drawing.
Region A is a case where the rotation speed n of the motor 20 that is a drive source for generating the reaction force is 0 or less than the minute rotation speed n *. This area A shows a scene where an operation on the pedal body 6 is started. In the scene where the operation on the pedal body 6 is started, the amount of change in the rotation speed n of the motor 20 increases when the motor 20 transitions from the stop state to the drive state, and thus overshoot is likely to occur.

  Region B is a case where the rotational speed n of the motor 20 is equal to or greater than the threshold Th and the change amount Δn of the rotational speed n is equal to or greater than the threshold Th #. The threshold value Th # is a threshold value that changes according to the rotational speed n (more specifically, it increases as the rotational speed n increases). This region B shows a scene where a pedaling force greater than the pedaling force is further applied from a state where a pedaling force is applied to the pedal body 6 by the driver. Also in this region B, since the amount of change Δn of the rotational speed n of the motor 20 is large, overshoot is likely to occur.

  FIG. 6 is a flowchart showing the flow of processing executed by the microcomputer 56. The processing of this flowchart is repeatedly executed at a predetermined cycle, for example.

  First, the microcomputer 56 receives the reaction force set value P from the host ECU 70 via the CAN control circuit 54 (step S100). Next, the microcomputer 56 detects the rotational speed n of the motor 20 based on the pulse width of the output voltage of the Hall IC 64 and the installation interval of small holes and slits provided in the motor casing (step S102). . Next, the microcomputer 56 determines whether or not the detected rotation speed n is 0 (step S104). Note that the processing in step S104 may determine whether or not the detected rotation speed n is less than the minute rotation speed n * as described above.

  When the detected rotation speed n is 0 (step S104: Yes), the microcomputer 56 performs friction suppression control for a predetermined time τ (step S106). That is, the microcomputer 56 gives the current command value Is to the motor driver IC 58 until the predetermined time τ has elapsed since the motor 20 starts to transition from the stopped state to the drive state, and supplies the motor 20 with a current based on the current command value Is. Let Accordingly, the reaction force output device 10 suppresses overshoot of reaction force (torque) that occurs when the motor 20 transitions from the stop state to the drive state.

  If the detected rotation speed n is not 0 (step S104: No), the microcomputer 56 determines whether or not the detected rotation speed n is equal to or greater than the threshold Th (step S108). If the detected rotation speed n is greater than or equal to the threshold Th (step S108: Yes), the microcomputer 56 determines whether or not the detected change amount Δn of the rotation speed n is greater than or equal to the threshold Th # (step S110).

The microcomputer 56 performs normal control when the detected rotation speed n is not equal to or greater than the threshold Th (step S108: No) or when the detected change amount Δn of the rotation speed n is less than the threshold Th # (step S110: No). This is performed (step S112). In other words, the microcomputer 56 gives the current command value Im to the motor driver IC 58 and causes the motor 20 to pass a current based on the current command value Im.
On the other hand, when the detected change amount Δn of the rotational speed n is greater than or equal to the threshold Th # (step S110: Yes), the microcomputer 56 performs friction suppression control (step S106).

  Next, the reaction force output device 10 outputs a reaction force based on the current controlled by the microcomputer 56 to the pedal body unit 2 (step S114). Thereby, the reaction force output apparatus 10 ends one routine of this flowchart.

  As described above, according to the reaction force output device 10 according to the present embodiment, when the setting condition indicating that reaction force overshoot is likely to occur, the ratio is compared with the current command value Im when the setting condition is not satisfied. Then, by giving a relatively small current command value Is to the reaction force set value P and energizing the motor 20 with a current based on the current command value Is, the reaction force is prevented from being output excessively. can do. As a result, the reaction force output device 10 can improve the accelerator feeling when the driver steps on the pedal body 6.

  As mentioned above, although the form for implementing this invention was demonstrated using embodiment, this invention is not limited to such embodiment at all, In the range which does not deviate from the summary of this invention, various deformation | transformation and substitution Can be added.

DESCRIPTION OF SYMBOLS 1 ... Accelerator pedal apparatus, 2 ... Pedal main body unit, 6 ... Pedal main body part, 10 ... Reaction force output device, 20 ... Motor, 30 ... Gear reduction mechanism, 50 ... Circuit board, 56 ... Microcomputer, 70 ... High-order ECU, 72 …engine

Claims (5)

A driving unit that outputs a force in a direction opposite to the operation direction with respect to an operator operated by a person by driving the driving member;
A control unit that determines a control amount to be given to the drive unit based on an input value, and when the setting condition indicating that a force overshoot in the direction opposite to the operation direction is likely to occur is satisfied, A control unit that performs friction suppression control that determines the control amount to be smaller than the input value as compared with a case where the setting condition is not satisfied;
Reaction force output device comprising. The control unit gradually increases the control amount until a predetermined period elapses after the setting condition is satisfied.
The reaction force output device according to claim 1. The drive unit is a motor,
The setting condition includes that the rotational speed of the motor is near zero.
The reaction force output device according to claim 1 or 2. The drive unit is a motor,
The setting condition includes that the rotational speed of the motor exceeds a threshold value and the change in the rotational speed of the motor is large.
The reaction force output device according to any one of claims 1 to 3. The setting condition includes that the rotational speed of the motor exceeds a threshold value, and a change in the rotational speed of the motor exceeds a second threshold value determined according to the rotational speed of the motor.
The reaction force output device according to claim 4.

Images