Seat belt device and vibration system thereof

Abstract

Provided is a seat belt device and a vibration system thereof, with which it is possible to provide an occupant with a comfortable skin sensation linked to various sound sources, including audio. In order to realize this, a vibration system (100) of a seat belt device (1) configured to wind up a seat belt (2) for a vehicle according to the present disclosure is a vibration system (100) including: an actuator provided to the seat belt device (1); and a control device that processes an input signal based on a predetermined vibration generation trigger to extract a rhythm component signal, performs pulse modulation processing that corresponds to the difference between the rhythm component signal and a predetermined threshold value for each fixed cycle, and drives the actuator in accordance with the pulse-modulated signal.

Description

Seatbelt device and its vibration system

[0001] The present invention relates to a seat belt device and its vibration system.

[0002] As a seat belt device for a vehicle, there has been proposed a device that provides a vibration stimulus to a passenger, particularly a driver, that is synchronized with the tempo of music (see, for example, Patent Document 1). There has also been proposed a device that conveys a warning or the like to a passenger as a tactile sensation transmitted through the skin, such as vibration or tension change (see, for example, Patent Document 2).

[0003] JP 2022-149732 A JP 2008-044570 A

[0004] However, the above-mentioned conventional devices have only been proposed with the main aim of establishing means for issuing warnings or alerts, such as gently notifying the driver of an abnormal speed change by varying the timing of the seat belt vibration (Patent Document 1) or providing a seat belt reminder function (Patent Document 2).In other words, there is no technology that uses a device that generates vibrations in a seat belt device for a different purpose, such as technology that provides a comfortable cutaneous sensation to the occupant linked to various sound sources, including audio.

[0005] Therefore, an object of the present invention is to provide a seat belt device and its vibration system that can give occupants a comfortable cutaneous sensation linked to various sound sources including audio.

[0006] One aspect of the present invention that has been devised to solve such problems is a vibration system for a seat belt device configured to retract a vehicle seat belt, the vibration system including: an actuator provided in the seat belt device; and a control device that processes an input signal based on a predetermined vibration generation trigger to extract a rhythm component signal, performs pulse modulation processing according to the difference between the rhythm component signal and a predetermined threshold at regular intervals, and drives the actuator according to the pulse-modulated signal.

[0007] In such a seatbelt vibration system, the vibration is synchronized with various vibration generation triggers, such as an audio sound source in the vehicle, and vibrations are generated according to the sound pressure level of the vibration generation trigger. By generating vibrations synchronized with the sound source in this way, a comfortable cutaneous sensation can be provided to the occupant. In this regard, conventional technology (e.g., Patent Document 1) simply generates the same vibrations for different songs with the same tempo, making it impossible to provide the occupant with a comfortable cutaneous sensation synchronized with the sound source.

[0008] In the vibration system of the seat belt device as described above, the control device may include a low-pass filter that attenuates high-frequency components of the input signal.

[0009] In the vibration system of the seat belt device as described above, the predetermined vibration generation trigger may be an audio signal of music being played in the vehicle cabin.

[0010] The vibration system of the seat belt device as described above may further include a spindle that retracts the seat belt, a drive motor that generates power to rotate the spindle, and a clutch that transmits power from the drive motor to the spindle when the drive motor rotates in one direction, and may use the drive motor as an actuator.

[0011] The drive motor in the vibration system of the seat belt device as described above may be a DC brush motor.

[0012] In the vibration system of the seat belt device as described above, the control device may reverse the rotation direction of the drive motor to release the clutch, and then rotate the drive motor in one direction to put the clutch into an engaged state.

[0013] In the vibration system of the seat belt device as described above, the clutch may be released at a timing when the drive motor is not operating in response to a pulse-modulated signal.

[0014] The vibration system of the seat belt device as described above may further include a tongue attached to the seat belt, a buckle to which the tongue is detachably attached, a bracket supporting the buckle, and a vibration motor provided in the buckle, and the motor may be used as an actuator.

[0015] In the vibration system of the seat belt device as described above, the vibration motor may be a DC brush motor with an eccentric weight.

[0016] In the vibration system of the seatbelt device as described above, if a rhythm component signal exceeding a predetermined threshold is shorter than a predetermined minimum operating time T_min, a compensating operating time T_add may be added to the signal by the control device.

[0017] In the vibration system of the seat belt device as described above, if a rhythm component signal that exceeds a predetermined threshold is longer than a predetermined maximum drive time T_max, the control device may stop the drive of the actuator for the portion of the signal that exceeds the maximum drive time T_max.

[0018] In the vibration system of the seat belt device as described above, the control device may temporarily increase the current value applied to the vibration motor at the beginning when driving the vibration motor in accordance with the pulse-modulated signal, and then decrease the current value thereafter.

[0019] In the vibration system of the seat belt device as described above, regenerative braking may be used before stopping the vibration motor that is driven in response to the pulse-modulated signal.

[0020] Another aspect of the present invention is a seat belt device including a vibration system as described above.

[0021] Yet another aspect of the present invention is a seat belt device for a driver's seat that is equipped with the vibration system described above, and when the control device detects that the seat belt has been pulled out by the driver leaning forward, for example, the control device stops the process of driving the actuator in accordance with the pulse-modulated signal, reverses the direction of rotation of the drive motor, and disengages the clutch, and when it detects that the driver has returned to his original position, the control device rotates the drive motor in one direction, engages the clutch, and resumes the process of driving the actuator in accordance with the pulse-modulated signal.

[0022] According to the present invention, it is possible to provide a seat belt device and its vibration system that can give a passenger a comfortable cutaneous sensation linked to various sound sources including audio.

[0023] 1 is an exploded perspective view of a motor, a power transmission mechanism, a final gear, a spindle, etc.; 2 is a diagram showing a schematic configuration of an ECU (control unit); 3 is a block diagram showing an example of the configuration of an ECU (control unit); 4 is a diagram showing a detailed configuration example from the signal generation unit of the ECU to the motor drive circuit; 5 is a diagram explaining a technique for extracting multiple high-pitched frequency bands and driving a motor with a more complex rhythmic component; 6 is a diagram explaining an example of generating a motor drive signal using a signal generation unit (signal processor) equipped with AI; 7 is a graph showing (A) changes in the signal level of a rhythmic component signal extracted by processing an input signal; (B) changes in motor current after performing pulse modulation processing according to the difference between the rhythmic component signal and a predetermined threshold at regular intervals; and (C) changes in belt tension when the drive motor is driven. 8 is a graph explaining pulse width modulation processing while showing changes in the rhythmic component signal and motor current. 9 is a graph showing (A) changes in the signal level of the rhythmic component signal and (B) changes in motor current, explaining compensation processing when the rhythmic component signal exceeds the predetermined threshold for a short period of time. 1 is a diagram illustrating a mode in which a vibration motor provided in a buckle is used to generate vibrations when the seat belt is not fastened.

[0024] FIG. 1 is a diagram illustrating a vibration motor provided in a buckle and an ECU connected to the vibration motor.

[0025] FIG. 1 is a diagram illustrating a drive example of a motor that generates vibrations by rotating an eccentric weight.

[0026] FIG. 1 is a diagram illustrating a mode in which a vibration motor provided in a buckle is used to generate vibrations when the seat belt is not fastened.

[0027] FIG. 1 is a diagram illustrating a mode in which a vibration motor provided in a buckle is used to generate vibrations when the seat belt is not fastened.

[0028] FIG. 1 is a diagram illustrating a mode in which a vibration motor provided in a buckle is used and an ECU connected to the vibration motor.

[0029] FIG. 2 is a diagram illustrating a drive example of a motor that generates vibrations by rotating an eccentric weight.

[0029] FIG. 2 is a diagram illustrating a mode in which a vibration motor provided in a buckle is used to generate vibrations.

[0029] FIG. 3 is a diagram illustrating a mode in which a vibration motor provided in a buckle is used and an ECU connected to the vibration motor.

[0029] FIG. 3 is a diagram illustrating a drive example of a motor that generates vibrations by rotating an eccentric weight.

[0029] FIG. 4 is a diagram illustrating a mode in which a vibration motor provided in a buckle is used and an ECU connected to the vibration motor.

[0029] FIG. 4 is a diagram illustrating a drive example of a motor that generates vibrations by rotating an eccentric weight.1 is a diagram illustrating another example of an input signal based on a vibration generation trigger, showing how one occupant connects a portable game console to the in-car network and enjoys the corresponding vibration, while the remaining occupants enjoy vibrations linked to the car audio.

[0023] FIG. 1 is a diagram illustrating another example of an actuator that generates vibration.

[0024] FIG. 1 is a diagram illustrating an example in which a seatbelt device with a vibration function is connected via a wired or wireless connection so that it can be recognized as a gamepad by a tablet or portable game console, allowing the execution of vibration commands in an application.

[0025] FIG. 1 is a diagram illustrating an example in which a terminal is connected via a car audio system and recognized as a gamepad, allowing the user to experience the vibration function using the vibration system of the seatbelt device.

[0026] FIG. 1 is a diagram illustrating an example of a method for linking the vibration system of a seatbelt device to watching movies or videos.

[0027] FIG. 1 is a diagram illustrating an example of a method for generating and driving a signal by analyzing and recognizing images and sounds in real time.

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a seat belt device and its vibration system according to the present invention will be described in detail below with reference to the drawings (see FIGS. 1 to 14).

[0025] [Outline of the Configuration of the Seatbelt Retractor] First, the outline of the configuration of the seatbelt retractor 4 that constitutes the seatbelt device 1 will be described (see FIG. 1).

[0026] The seat belt retractor 4 is a device for a vehicle configured to retract the seat belt 2. The seat belt retractor 4 of this embodiment is a motorized retractor for a motorized seat belt (sometimes called a "PP" (Pre-Pretensioner)) that retracts the seat belt 2 by the power of a motor, and is composed of a spindle 10, a drive motor 20, a power transmission mechanism 30, a final gear 33, a clutch 34, etc. (see FIG. 1 ).

[0027] The spindle 10 is a member that retracts the seat belt 2 and is provided so as to be rotatable forward and reverse around a central axis (see FIG. 1). For convenience, in this specification, the forward rotation direction of the spindle 10, etc., to retract the seat belt 2 will be referred to as the "retracting direction," and the reverse rotation direction to unreel the seat belt 2 will be referred to as the "clutch releasing direction."

[0028] The drive motor 20 is a power source that generates power to rotate the spindle 10. When the drive motor 20 is rotated in one direction (referred to as the "first direction" in this specification), the power is transmitted by the clutch 34, and the spindle 10 rotates in the winding direction. When the motor 20 is rotated in a second direction opposite to the first direction, the final gear 33 rotates in the clutch release direction (see FIG. 1).

[0029] The power transmission mechanism 30 is a mechanism for transmitting the power of the drive motor 20 to the spindle 10. For example, in this embodiment, the power transmission mechanism 30 includes a motor gear 31, a transmission shaft (intermediate gear) 32, a final gear 33, and a clutch 34. The motor gear 31 is composed of a worm attached to the output shaft 21 of the drive motor 20 (see FIG. 1). The transmission shaft 32 is a member for transmitting the power of the drive motor 20 to the final gear 33. The transmission shaft 32 is provided with a first helical gear 32a that meshes with the motor gear 31 and a second helical gear 32b that meshes with the final gear 33 (see FIG. 1).

[0030] The final gear 33 is one of the gears that make up the power transmission mechanism 30, and is made up of a large-diameter helical gear that is rotatably arranged on the central axis of the spindle 10. The final gear 33 in this embodiment is a gear that is arranged at the end of the gear train that makes up the power transmission mechanism 30. The outer periphery of the final gear 33 is formed with helical teeth (helical teeth) 33a that mesh with the second helical gear 32b of the transmission shaft 32.

[0031] The clutch 34 is a mechanism for transmitting or blocking the rotation of the final gear 33 to the spindle 10, and is disposed between the final gear 33 and the spindle 10 (see FIG. 1). In this embodiment, a so-called one-way clutch is used for the clutch 34, which is in an engaged state when the drive motor 20 is rotated in a first direction, transmitting the rotation of the final gear 33 to the spindle 10, and is not engaged when the motor 20 is rotated in a second direction. The configuration of the one-way clutch itself is similar to that of the conventional seat belt retractor 4, and therefore detailed description thereof will be omitted in this specification. However, for example, the one-way clutch may include a one-way clutch pawl (latch) 34b that engages with the ratchet gear 35a only when the final gear 33 rotates in one direction (see FIG. 1).

[0032] [Vibration System for Seat Belt Device] The vibration system 100 of the seat belt device 1 according to the present invention is linked to various vibration generation triggers and expresses or realizes vibrations corresponding to the sound pressure levels of the vibration generation triggers, thereby providing a comfortable skin sensation to the occupant. The vibration system 100 of this embodiment is configured to include an ECU (controller) 200 that applies a predetermined current to an actuator, for example, a drive motor 20, to control the actuator to perform a specific drive.

[0033] Various types of vibration generation triggers can be used. As an easy-to-understand example, the following describes a case where a signal from an in-car audio sound source is used as the vibration generation trigger. The in-car audio sound source may be an in-car audio sound source, or may be a sound source transmitted wirelessly or via a wire from a portable device such as a music playback terminal 300 (see FIG. 2, etc.).

[0034] The ECU 200 includes an audio I / F 210, an AD conversion signal processing unit 220, a signal mixing / selection unit 230, a signal generation unit (signal processor) 240, a comparator 250, and a motor drive circuit 260 (see FIGS. 2 and 3A).

[0035] A signal such as music is input to the audio I / F 210 from an audio sound source. If the input signal is analog, the AD conversion signal processing unit 220 converts the signal into digital (see FIG. 3A). The signal mixing / selection unit 230 receives digital signals input from the audio I / F 210 or signals converted to digital by the AD conversion signal processing unit 220, as well as operation signals transmitted from a portable device connected wirelessly or via a wire, and mixes or selects the signals for output. Note that the ECU 200 of this embodiment is also configured to receive alarm requests from safety monitoring devices, such as signals informing of a danger to the vehicle, via the signal mixing / selection unit 230 (see FIG. 3A).

[0036] The audio signal input from the audio I / F 210 is not limited to an in-vehicle audio signal, but may also be a signal transmitted from a terminal 300 such as a mobile terminal (e.g., a smartphone) (see FIG. 2). The mobile terminal can be connected via a wired or wireless connection. If the audio signal is an analog signal, it is converted into a digital signal (software-based digital processing) and then converted into an actuator drive signal if the connection is via a wired connection. If the audio signal is a digital signal (possibly input via S / PDIF, HDMI (registered trademark), etc.), electrical or optical information is received and passed through a decoder to generate a drive signal. Alternatively, if the connection is wireless using a wireless standard such as Bluetooth (registered trademark), the audio signal is captured and similar processing is performed.

[0037] The signal generating unit 240 processes the signal output from the signal mixing / selecting unit 230 to extract a rhythm component signal, and periodically performs pulse modulation based on the difference between the rhythm component signal and a predetermined threshold value, thereby processing the input trigger signal so that it can be used as motor drive timing. The signal generating unit 240 in the ECU 200 of this embodiment is equipped with a low-pass filter (LPF) that attenuates high-frequency components of the input signal (see FIG. 3A). Alternatively, a high-pass filter (HPF) that attenuates low-frequency components of the input signal may be installed. For example, if the input signal is a music signal, the signal generating unit 240 may be equipped with a function that reads genre information, etc., contained in recent digital sound sources and selects an appropriate operation.

[0038] Here, we will explain the extraction of rhythmic signal components as a specific example of the signal generation unit 240. Figure 3B shows the flow of extracting bass signal components and extracting rhythmic components in a detailed example configuration from the signal generation unit 240 to the motor drive circuit 260. Here, the bass components are extracted using the LPF 240L, and the excess DC components are attenuated using the HPF 240H, thereby reducing unnecessary operation during subsequent threshold determination. Instead of the two filters, the LPF 240L and the HPF 240H, a combined bandpass filter BPF 240B (see Figure 3C) may be used. Note that reference numerals 242, 244, and 246 represent a rectifier, a smoothing circuit, and a modulation circuit, respectively (see Figure 3B).

[0039] The above-described example focuses on driving the rhythm of only the bass frequency band (see FIG. 3B). However, other methods are also conceivable, such as extracting multiple higher frequency bands and driving the system with more complex rhythmic components (see FIG. 3C). In this case, the signal generator 240 may be configured with analog circuits, such as filters, or software processing digital signals. Alternatively, the entire ECU (control unit) 200 may be implemented by software. For example, if the blocks shown in FIG. 3C are configured by software, the user may be able to enable or disable the frequency bands to be used, allowing adjustments to the user's preferences.

[0040] In addition to the above-mentioned methods, a signal generation unit (signal processor) 240 equipped with AI may be used to generate a motor drive signal by performing pattern recognition of music such as input audio signals, analyzing genres, beats, etc. (see FIG. 3D).

[0041] Comparator 250 outputs a signal for driving, for example, drive motor 20 in response to the signal output from signal generating unit 240. Motor driving circuit 260 passes a current (of a constant current value) for driving, for example, drive motor 20 based on the signal output from comparator 250 through motor connection line 270 (see FIG. 2 ).

[0042] When the drive motor 20 mounted on the seatbelt retractor 4 is a DC motor, the retracting torque of the seatbelt 2 is controlled by controlling the applied current via various gears in the power transmission mechanism 30. However, with regard to the retracting torque of the seatbelt 2, it can be difficult to generate a retracting force that changes continuously over time due to static friction in the drive mechanism, such as gears. In this regard, a vibration motion that repeatedly stops retracting from a stationary state momentarily is relatively easy to achieve, and this motion can be used to realize a tactile sensation whose intensity changes continuously over time. An example of signal processing when such a vibration motion is performed by the ECU 200 will be described below, showing example waveforms (see FIGS. 4 and 5). After the rhythm component signal is extracted through processing by the signal generation unit 240, pulse width modulation (PWM conversion) is performed at regular PWM cycles according to the difference between the rhythm component signal and a predetermined threshold (see FIGS. 4A and 5). In this case, when the difference between the rhythm component signal and the threshold value is large, the PWM duty increases, lengthening the drive time of the drive motor 20. Conversely, when the difference between the rhythm component signal and the threshold value is small, the PWM duty (i.e., motor drive time / PWM cycle [%]) decreases, shortening the drive time of the drive motor 20 (see FIGS. 4B and 5). The longer the drive time of the drive motor 20, the more the seat belt 2 is wound up, and the greater the tension of the seat belt 2 (see FIG. 4C). In this way, by controlling the time for which current is passed through the drive motor 20 using PWM, it is possible to apply intermittent changes to the tension of the seat belt 2. From the perspective of the occupant, such intermittent changes in the tension of the seat belt 2 are perceived as a pleasant vibration linked to the rhythm component of the sound source, or in other words, the sound pressure level of the sound source, via their skin sensation. The vibration system 100 of the seatbelt device 1 that generates such vibrations can be a particularly effective configuration when targeting a vibration generation trigger whose level changes over time, such as an audio source signal.

[0043] Furthermore, when a DC brush motor is used as the drive motor 20, which is the actuator that generates vibration, vibration may be generated while the ECU 200 performs processing to reduce uneven wear of the commutator within the drive motor 20. In the vibration system 100 of this embodiment, the drive motor 20, which was rotating in a first direction (winding direction), is reversed to a second direction (clutch release direction) midway to release the clutch 34, and then the drive motor 20 is gently rotated again in the first direction (winding direction) to engage the clutch 34. This changes the position of the brush within the drive motor 20, prevents the brush from concentrating in a narrow operating range, and reduces uneven wear of the commutator. In this case, it is preferable to release the clutch during a non-operating period or within an extremely short period when tension on the seat belt 2 is not required. For example, when vibration is synchronized with a signal from an audio sound source, if a signal with a certain degree of regularity is input (see FIG. 8A), the drive motor 20 can be reversed in the second direction (clutch release direction) at a timing (non-operation period) when the drive motor 20 is not operating for vibration and during a period when the retracting operation of the seat belt 2 is not affected, for example, at the timing indicated by the symbol "a" in FIG. 8B, to autonomously release (release) the clutch 34 (see FIG. 8). In this way, if the clutch is autonomously released at a timing when the drive motor 20 is not operating in accordance with a pulse-modulated signal, the retracting operation of the seat belt 2 is not affected.

[0044] [Another Example of Seatbelt Device Vibration System] So far, we have described an embodiment in which vibration is generated by driving the drive motor 20 that constitutes the seatbelt retractor 4, but other motors can also be used as actuators for generating vibration. As another embodiment, a case in which a vibration motor 90 provided in the buckle 70 is used will be described below (see FIGS. 9 and 10 ).

[0045] The seatbelt device 1 in this example includes a tongue 2t attached to the seatbelt 2, a buckle 70 configured to detachably mount the tongue 2t, a buckle stay (bracket) 80 supporting the buckle 70, and a vibration motor 90 mounted on the buckle 70 (see FIGS. 9 and 10 ). The vibration motor 90 is a relatively inexpensive vibration actuator. In this embodiment, a DC brush motor having an eccentric weight that generates vibrations through rotation of the eccentric weight is used as the vibration motor 90 (see FIG. 103). Note that, in addition to such a motor, an actuator that generates vibrations through reciprocating motion can also be used. When the vibration motor 90 is mounted on the buckle 70 as in this example, vibrations can be transmitted to the seat 5 through the buckle stay 80, and the device can also be used as a device that vibrates the seat 5 in response to an audio signal. Furthermore, when the vehicle is stopped, the vibration system 100 can be used to vibrate the seat 5 even when the seatbelt 2 is not fastened. Incidentally, in order to transmit vibrations efficiently, it is necessary to change the frequency when transmitting vibrations to the user via the seat belt 2 when the seat belt is fastened, and when transmitting vibrations to the seat without the seat belt fastened. The rotation speed of these motors (actuator operating frequency) is switched by a switch signal that notifies the buckle engagement.

[0046] While motors that generate vibrations by rotating an eccentric weight as described above are generally suited to generating constant, continuous vibrations, they require time to receive a signal and generate vibrations, and the inertial motion of the weight makes it difficult to immediately stop the vibrations. In other words, such motors are not good at generating vibrations with small variations. Therefore, a control method must be devised to achieve the same effect as when using the drive motor 20 that drives the seat belt retractor 4. Taking this into consideration, in this embodiment, the ECU 200 temporarily increases the current value applied to the vibration motor 90 in the initial stage of driving the vibration motor 90 in response to a pulse-modulated signal, and then decreases the current value to converge so that the vibration does not become too large (see FIG. 11 ). More specifically, a strong current is applied for a short period of time in the initial stage of driving, as indicated by the symbol b in FIG. 11 , and then the current is decreased to prevent the rotation from increasing too much, thereby eliminating the start-up delay. Furthermore, when it is desired to stop the vibration motor 90 as shown by the symbol c, in order to deal with the residual vibration caused by the inertial movement of the weight, it is possible to stop the motor using, for example, a regenerative brake, thereby making it possible to clearly distinguish between the on and off states of the vibration.

[0047] When vibration is generated by the rotation of an eccentric weight using an in-vehicle audio source or the like as a vibration generation trigger as described above, depending on the trigger source (such as the sound source that serves as the trigger), the duration of the input signal to be activated may be short, making it difficult for an actuator such as the drive motor 20 to fully respond and vibrate sufficiently. To address this issue, this embodiment sets a minimum activation time T_min, and if a rhythm component signal that exceeds a predetermined threshold is shorter than the minimum activation time T_min, the ECU 200 adds a compensatory activation time T_add to the signal (see FIG. 6 ). This makes it possible to sufficiently vibrate the actuator even if the time axis width of the rhythm component signal that exceeds the predetermined threshold is short.

[0048] Conversely, if the trigger signal has a long time axis width (signal duration), the actuator may be activated only around the peak of the trigger signal that is the intended activation time and then stopped. This type of processing is particularly effective when linking with a music signal, in which only the rhythmic peaks are desired to be conveyed to the occupant as vibrations. In this embodiment, a maximum activation time T_max is set, and if the portion of the rhythm component signal that exceeds the threshold is longer than the maximum activation time T_max, the ECU 200 stops activation of the actuator for the portion of the signal that exceeds the maximum activation time T_max (see FIG. 7). Incidentally, if the minimum activation time T_min and maximum activation time T_max settings can be changed by the occupant or user via a terminal such as a portable device, the user can adjust the vibration mode to suit their preferences.

[0049] [Example of control of seat belt device for driver] When a driver uses the seat belt device 1 equipped with the vibration system 100 as described above, the driver may find it difficult to assume a leaning forward posture when the seat belt 2 is retracted. In order to improve usability in such a situation, the following control may be implemented so that when a user (in this case, the driver) applies force in a direction to pull out the seat belt 2, the seat belt 2 is released or mechanically pulled out. A specific control example will be described below (see FIG. 12 ).

[0050] First, a sensor (not shown) is used to monitor whether the driver has moved in the direction of unwinding the seat belt 2, for example, by leaning forward (step SP1). If it is detected that the seat belt 2 has been unwound (Yes in step SP2), a control device, such as the ECU 200, stops the process of driving the actuator (in this example, the drive motor 20) in accordance with the pulse-modulated signal, reverses the direction of rotation of the drive motor 20, and disengages the clutch 34 (step SP3). Thereafter, the sensor monitors whether the driver has returned to their original posture based on the movement of the seat belt 2 (step SP4). If it is detected that the driver has returned to their original posture (Yes in step SP5), the sensor rotates the drive motor 20 in one direction to gently engage the clutch 34 (step SP6). Then, it resumes the process of driving the drive motor 20 to vibrate in response to the pulse-modulated signal in conjunction with a sound source or the like (step SP7).

[0051] [Another Example of Input Signal Based on Vibration Generation Trigger] Up to this point, the vibration system 100 has been described using an example in which a sound source signal, such as in-vehicle audio, is used as a vibration generation trigger. However, such a sound source signal is, of course, merely one example of a vibration generation trigger. That is, assuming that each occupant wears a seatbelt 2 individually, the seatbelt 2 can also be used to allow each occupant to enjoy entertainment through a tactile sensation. For example, if occupants other than the driver enjoy games on a network-connectable portable game console or smartphone, those devices (indicated by reference numeral 300 in FIG. 13 ) can be connected to the in-vehicle network. In response to a vibration generation trigger using the game's background music or sound effects as a sound source signal, or even a vibration generation trigger linked to visual elements such as visual effects, the vibration system 100 of the seatbelt device 1 for that occupant's seat can be activated or vibrated, thereby achieving an effect that can only be experienced by that occupant (see FIG. 13 ). Meanwhile, other occupants can use their car audio to enjoy the effect of seatbelt vibrations corresponding to the sound source.

[0052] [Other Examples of Actuators That Generate Vibrations] Up to this point, examples using the drive motor 20 and the vibration motor 90 as actuators have been shown, but these are merely preferred examples of actuators that generate vibrations based on a predetermined vibration generation trigger such as a sound source signal, and other types of devices can also be used. To give a specific example, the actuator that generates vibrations or tension changes may be the seat belt retractor 4, buckle 70, tongue 2t, shoulder anchor 92 or its base (not shown), outer anchor 94, or an actuator (indicated by reference numeral 22 in FIG. 14) attached to, sewn into, or mounted on (the webbing of) the seat belt 2 included in the seat belt device 1 (see FIG. 14). (In FIG. 14, locations where such a motor can be located are indicated by the reference numeral "*".)

[0053] As described above, the vibration system 100 of the seat belt device 1 of this embodiment is linked to various vibration generation triggers, including audio sound sources in the vehicle, and vibrations corresponding to the vibration generation triggers are expressed in each seat. In this way, the vibration system 100 of this embodiment is able to provide a comfortable cutaneous sensation to the occupant by generating vibrations linked to sound sources, etc., and is therefore significantly different from conventional technology, which simply vibrates in the same way for different songs with the same tempo. The seat belt device 1 with the above functions can be used in all seats regardless of their location in the vehicle.

[0054] Further functions, uses, or effects that can be achieved by the vibration system 100 of this embodiment are as follows: 1) It is possible to more effectively improve the sense of realism of entertainment using the seat belt device 1. 2) The seat belt device 1 can also be used as a device to wake up drivers while driving. 3) It can also be used as a more effective vibration warning device. 4) Active use of the seat belt 2 contributes to an increase in the rate at which the seat belt 2 is worn. 5) A function to generate vibrations in response to a vibration generation trigger can be realized using only one or both of the drive motor 20 of the seat belt retractor 4 and the vibration motor 90 of the buckle 70. 6) When the vehicle is stopped, it is also possible to transmit the vibrations of the buckle 70 via the seat 5. 7) It is possible to provide the seat belt 2 with multiple functions. 8) Since the seat belt 2 is worn by each occupant, it can be used independently.

[0055] The above-described embodiment is one example of a preferred embodiment of the present invention, but is not limited to this, and various modifications are possible within the scope of the present invention. For example, although not particularly shown, in the vibration system 100 of the seat belt device 1 described above, instead of or at the time of processing signals in the ECU 200, a sound source such as music may be recognized by AI, and processing including a modulation process may be performed.

[0056] Furthermore, while vibration of the seat belt 2 has traditionally been used for warning purposes, such as signaling a danger to the occupants (particularly the driver) of a vehicle, in recent years, improvements in collision safety functions have led to the development of functions for analyzing danger based on surrounding conditions. In light of this, the vibration system 100 of the present embodiment can be linked to these ever-improving collision safety functions to stop entertainment functions, such as music-linked operations, when danger approaches, or to issue an alarm after stopping the entertainment functions to alert the occupants of a danger in the surroundings. Such functions can be implemented by linking a vehicle-side controller (not shown) with the ECU 200 using an alarm request (see FIG. 3A ), such as a signal indicating a danger to the vehicle, received by the signal mixing / selection unit 230.

[0057] Furthermore, when the drive motor 20 of the seat belt retractor 4 is used as an actuator for generating vibrations as in the above-described embodiment, a method can be adopted in which the seat belt 2 is vibrated or the tension is changed by repeatedly winding and stopping the seat belt 2, or winding and releasing the tension.

[0058] Furthermore, in the above-described embodiment, a case where passengers other than the driver enjoy games on a network-connectable portable game console or smartphone has been described. This will be further explained below. Recently, terminals 300, such as control devices (hereinafter also referred to as game pads) that can be connected to PCs or tablets, have become available on the market. These devices often include a vibration device to enhance the sense of realism of the game. When playing games using such a terminal 300 in a vehicle, the seat belt apparatus 1 equipped with the vibration function described above may be connected to the tablet or portable game console via a wired or wireless connection so that the tablet or portable game console can recognize it as a game pad and execute vibration commands in the application (see FIG. 15 ). Alternatively, the terminal 300 described above may be connected via a car audio system and recognized as a game pad, allowing the user to experience the vibration function using the vibration system 100 of the seat belt apparatus 1 (see FIG. 16 ).

[0059] The vibration system 100 of the seat belt device 1 can also be used for watching movies and other video applications. For example, the motions of characters and vehicles, being grabbed or hit, the movement of light, air, and water, and emotions (surprise, tension, etc.) depicted in movies can be reproduced by the vibration or tension changes of the seat belt device 1. These changes can be gradual or sudden, and many gradual and sudden tension changes of the seat belt device 1 that are associated with the depictions depicted in movies can be preset and linked to the playback of the movie software. Possible methods for linking actions include a method of directly importing signals contained in the software (see FIG. 17), as in the case of the above-mentioned game, and a method of generating signals by analyzing and recognizing images and sounds in real time (see FIG. 18).

[0060] The present invention is suitable for application to a seat belt device and its vibration system.

[0061] DESCRIPTION OF SYMBOLS 1...Seat belt device 2...Seat belt 2t...Tongue 4...Seat belt retractor 5...Seat 10...Spindle 20...Drive motor (actuator) 21...Output shaft 22...Drive motor (actuator) 30...Power transmission mechanism 31...Motor gear 32...Transmission shaft 32a...First helical gear 32b...Second helical gear 33...Final gear (first rotary gear) 33a...Helical 34...Clutch 34b...One-way clutch pawl 35a...Ratchet gear 70...Buckle 80...Buckle stay (bracket) 90...Vibration motor (actuator) 92...Shoulder anchor 94...Outer anchor 100...Vibration system 200...ECU (controller) 210...Audio I / F 220...AD conversion signal processing unit 230...Signal mixing / selection unit 240...Signal generation unit 240B...BPF 240H...HPF 240L...LPF 242...Rectifier 244...Smoothing circuit 246...Modulation circuit 250...Comparator 260...Motor drive circuit 270...Motor connection line 300...Terminal such as game machine T_min...Minimum operating time T_add...Compensation operating time T_max...Maximum operating time

Claims

1. A vibration system for a seat belt device configured to retract a vehicle seat belt, comprising: an actuator provided in the seat belt device; and a control device that processes an input signal based on a predetermined vibration generating trigger to extract a rhythm component signal, performs pulse modulation processing according to the difference between the rhythm component signal and a predetermined threshold at regular intervals, and drives the actuator according to the pulse modulated signal.

2. The vibration system of a seat belt device according to claim 1, wherein the control device is provided with a low-pass filter for attenuating high-frequency components of the input signal.

3. The vibration system of claim 2, wherein the predetermined vibration generation trigger is an audio signal of music being played in the vehicle cabin.

4. A vibration system for a seat belt device as described in any one of claims 1 to 3, further comprising: a spindle for winding up the seat belt; a drive motor for generating power to rotate the spindle; and a clutch for transmitting power from the drive motor to the spindle when the drive motor rotates in one direction, wherein the drive motor is used as the actuator.

5. The vibration system of claim 4, wherein the drive motor is a DC brush motor.

6. The vibration system of a seat belt device according to claim 5, wherein the control device reverses the rotation direction of the drive motor to release the clutch, and then rotates the drive motor in one direction to engage the clutch.

7. The vibration system of a seat belt apparatus according to claim 6, wherein the clutch is released at a timing when the drive motor is not operated in response to the pulse-modulated signal.

8. A vibration system for a seat belt device as described in any one of claims 1 to 3, further comprising a tongue attached to the seat belt, a buckle to which the tongue is detachably attached, a bracket supporting the buckle, and a vibration motor provided in the buckle, the motor being used as the actuator.

9. The vibration system of claim 8, wherein the vibration motor is a DC brush motor having an eccentric weight.

10. The vibration system of a seat belt device according to claim 9, wherein if any of said rhythm component signals exceeding said predetermined threshold is shorter than a predetermined minimum operating time T_min, a compensatory operating time T_add is added to said signal by said control device.

11. A vibration system for a seat belt device as described in claim 9, wherein, when the portion of the rhythm component signal that exceeds the predetermined threshold is longer than a predetermined maximum drive time T_max, the control device stops the drive of the actuator for the portion of the signal that exceeds the maximum drive time T_max.

12. A vibration system for a seat belt device as described in claim 9, wherein the control device temporarily increases the current value applied to the vibration motor at an initial stage when driving the vibration motor in response to the pulse-modulated signal, and then decreases the current value.

13. The vibration system of claim 9, further comprising: a regenerative brake that is used before stopping the vibration motor that is driven in response to the pulse-modulated signal.

14. A seat belt device comprising a vibration system according to any one of claims 1 to 3.

15. A seat belt device for a driver's seat equipped with the vibration system of claim 4, wherein, when the control device detects that the seat belt has been pulled out by the driver leaning forward, for example, the control device stops the process of driving the actuator in accordance with the pulse-modulated signal and reverses the rotation direction of the drive motor to release the clutch, and, when the control device detects that the driver has returned to his or her original posture, the control device rotates the drive motor in one direction to connect the clutch, and resumes the process of driving the actuator in accordance with the pulse-modulated signal.

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