Patent Application
20200156689
This application is based on and claims priority under 35 U.S.C. § 119 to Japanese Patent Application 2018-215768, filed on Nov. 16, 2018, the entire contents of which are incorporated herein by reference.
This disclosure relates to a steering device.
In the related art, a vehicle steering is provided with a sensor element for detecting the gripped state by a driver and a heating element (heater wire) for warming the steering (a grip portion thereof). For example, Reference 1 discloses a circuit configuration in which an intermittent operation of a heater due to an operation of an automatic thermostat reduces influence on grip detection using a sensor element (capacitance sensor) provided in the steering. Further, for example, Reference 2 discloses a configuration in which driving of the sensor element and driving of the heater are alternately performed (selectively switched). As a result, it is possible to detect the gripped state by a driver with high accuracy while warming the steering.
However, in a vehicle, further improvement is being made to all components. Then, since the above-described steering device cannot always be said to satisfy a required level thereof by the configuration of the related art, there is still room for improvement in this respect.
Thus, a need exists for a steering device which is not susceptible to the drawback mentioned above.
A steering device according to an aspect of this disclosure includes a sensor drive unit configured to drive a sensor element provided in a steering to detect a gripped state of the steering, and a heater drive unit configured to drive a heater provided in the steering, in which the sensor drive unit executes driving of the sensor element periodically at an interval, the heater drive unit executes heater driving alternately with sensor driving by the sensor drive unit, and the interval of sensor driving is expanded in a state where the steering is gripped, compared with a state where the steering is not gripped.
The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed description considered with the reference to the accompanying drawings, wherein:
Hereinafter, a first embodiment specifying a vehicle steering device will be described with reference to the drawings.
As illustrated in
Specifically, in the steering 1 of the present embodiment, a sensor electrode 11a of the capacitance sensor 11 and a heater wire 12a of the heater 12 are respectively provided inside a skin 1s which covers the outer surface of the steering 1. Moreover, the sensor electrode 11a and the heater wire 12a of the present embodiment are configured as separate elements independent of each other. Further, the sensor electrode 11a and the heater wire 12a are disposed over substantially the entire region in the direction in which the steering 1 extends, specifically, the direction in which the rim 2 having an annular shape extends. In the present embodiment, a steering device 20 is thus configured to warm the steering 1 and detect the gripped state of the steering 1 by the driver.
Specifically, as illustrated in
Further, as illustrated in
More specifically, the heater drive unit 22 of the present embodiment executes heater driving alternately with sensor driving by the sensor drive unit 21 described above. That is, the heater drive unit 22 executes heater driving in an interval during which the sensor drive unit 21 does not perform sensor driving. The steering device 20 of the present embodiment is thus configured to prevent execution of heater driving from affecting grip detection of the steering 1 using the capacitance sensor 11.
Further, as illustrated in
Next, actions and effects of the present embodiment will be described.
(1) That is, in the above-described configuration in which sensor driving and heater driving are alternately executed, when the interval of sensor driving is expanded (t0→t1), the execution time of heater driving is also extended (the rate at which heater driving is executed being increased). As a result, the steering 1 gripped by the driver can be effectively warmed. Then, in addition to this, power saving can be achieved when the steering 1 is not gripped.
(2) Further, in the configuration in which the capacitance sensor 11 is used for the sensor element 10, for example, when heater driving and sensor driving are performed at the same time, a possibility of affecting detection of the gripped state of the steering 1 is increased. Accordingly, with the above configuration, the gripped state can be detected with high accuracy.
(3) The sensor electrode 11a and the heater wire 12a are configured as separate elements. Therefore, it is possible to more effectively prevent execution of heater driving from affecting grip detection of the steering 1 using the capacitance sensor 11.
Hereinafter, a second embodiment specifying the vehicle steering device will be described with reference to the drawings. Moreover, for convenience of explanation, the same components as those in the first embodiment will be denoted by the same reference numerals, and a description thereof will be omitted.
As illustrated in
Specifically, the traveling state determination unit 33 of the present embodiment determines that the vehicle is in a traveling state when the vehicle speed V exceeds a predetermined speed V0 (V>V0). Further, the traveling state determination unit 33 determines that the vehicle is stopped when the vehicle speed V is equal to or less than the predetermined speed V0 (V≤V0). Then, the control device 30B of the present embodiment is configured to change the interval of sensor driving by the sensor drive unit 21B on the basis of the determination result of the traveling state determination unit 33.
More specifically, as illustrated in the flowchart of
For example, as illustrated in
That is, in a state where the vehicle is in a traveling state and the steering 1 is gripped, it is estimated that there is a high possibility of the gripped state being maintained thereafter. Accordingly, in such a case, the steering 1 can be effectively warmed by expanding the interval of sensor driving and extending the execution time of heater driving.
Further, in a state where the steering 1 is not gripped even though the vehicle is in a traveling state, it is estimated that there is a high possibility of the steering 1 being gripped thereafter. Accordingly, in such a case, the gripped state of the steering can be determined with high accuracy by increasing the frequency at which sensor driving is executed.
Hereinafter, a third embodiment of the vehicle steering device will be described with reference to the drawings. Moreover, for convenience of explanation, the same components as those in the first embodiment will be denoted by the same reference numerals, and a description thereof will be omitted.
As illustrated in
In the control device 30C of the present embodiment, the steering state determination unit 34 determines that the steering 1 is in a steered state when the steering angle θs (absolute value thereof) exceeds a predetermined angular range (|θs|>θ0). Further, when the steering angle θs (absolute value thereof) is within the predetermined angular range (|θs|θ0), the steering state determination unit 34 determines that the steering 1 is not in a steered state. Then, the control device 30C of the present embodiment is configured to change the interval of sensor driving by the sensor drive unit 21C on the basis of the determination result of the steering state determination unit 34.
Specifically, as illustrated in
That is, when the steering 1 is in a steered state, it is estimated that there is a high possibility of the steering 1 being in a gripped state. Then, it is estimated that there is a high possibility of the gripped state of the steering 1 being continued thereafter. Accordingly, in such a case, the steering 1 can be effectively warmed by expanding the interval of sensor driving and extending the execution time of heater driving.
In addition, the embodiment may be changed and implemented as follows. The above embodiment and following modifications may be implemented in combination with each other within a technically consistent range.
In each of the above embodiments, heater driving is executed on the basis of an operation input to the heater switch 32, but, as illustrated in
In the second embodiment, the traveling state determination unit 33 determines that the vehicle is in a traveling state when the vehicle speed V exceeds the predetermined speed V0 (V>V0). However, the disclosure is not limited thereto, and traveling determination of the vehicle may be performed using, for example, a control signal or a state quantity of the vehicle such as a brake signal, a parking brake signal, an accelerator opening degree, or a shift state. Then, in the third embodiment, the steered state of the steering 1 may also be determined using other vehicle state quantities or control signals.
In the second embodiment, when the steering 1 is gripped even though the vehicle is stopped, the interval of sensor driving may be expanded, compared with a state where the steering 1 is not gripped. Then, under a condition that the vehicle is in a traveling state, the interval of sensor driving may be extended when the steering 1 is gripped, and in other words, the interval of sensor driving may not be extended when the vehicle is stopped.
In each of the above embodiments, the sensor electrode 11a of the capacitance sensor 11 and the heater wire 12a of the heater 12 are configured as separate elements. However, the disclosure is not limited thereto, and may also be applied to a configuration in which the sensor electrode 11a and the heater wire 12a are connected in a circuit. Then, the disclosure may also be applied to a configuration in which the sensor electrode 11a functions as the heater wire 12a.
In the above embodiment, the sensor electrode 11a and the heater wire 12a are disposed over substantially the entire region in the direction in which the steering 1 extends, more specifically, in the direction in which the rim 2 serving as a grip portion thereof extends, the number and arrangement of sensor elements 10 and heaters 12 provided in the steering 1 may be arbitrarily changed.
In each of the above embodiments, the capacitance sensor 11 is used as the sensor element 10 for detecting the gripped state of the steering 1, but the disclosure may also be applied to a configuration using, for example, any other sensor element 10 such as a pressure sensor. Then, the heater 12 may also be formed using, for example, a thermoelectric element such as a Peltier element.
In addition to changing the interval of sensor driving, an aspect of heater driving, specifically, the amount of energization current may be changed. For example, when the interval of sensor driving is expanded, an excessive increase in temperature can be prevented by decreasing the amount of energization current to the heater 12. Further, conversely, the steering 1 can be rapidly warmed by increasing the amount of energization current to the heater 12 in accordance with expansion of the interval. Furthermore, when the interval of sensor driving is shortened, further power saving can be achieved by decreasing the amount of energization current to the heater 12. Then, conversely, a reduction in temperature can be prevented by increasing the amount of energization current to the heater 12.
Next, a technical idea that may be grasped from the embodiments and modifications will be described.
(A) By a steering device in which the sensor element is a capacitance sensor and the capacitance sensor and the heater are provided as separate elements, it is possible to more effectively prevent execution of heater driving from affecting grip detection of a steering using a capacitance sensor.
A steering device according to an aspect of this disclosure includes a sensor drive unit configured to drive a sensor element provided in a steering to detect a gripped state of the steering, and a heater drive unit configured to drive a heater provided in the steering, in which the sensor drive unit executes driving of the sensor element periodically at an interval, the heater drive unit executes heater driving alternately with sensor driving by the sensor drive unit, and the interval of sensor driving is expanded in a state where the steering is gripped, compared with a state where the steering is not gripped.
That is, in a configuration in which sensor driving and heater driving are alternately executed, when the interval of sensor driving is expanded, the execution time of heater driving is also extended. Accordingly, with the above configuration, the steering gripped by the driver can be effectively warmed. Then, in addition to this, power saving can be achieved when the steering is not gripped.
It is preferable that the steering device further includes a traveling state determination unit configured to determine a traveling state of a vehicle, and the interval of sensor driving is expanded in a state where the vehicle is in a traveling state and the steering is gripped, compared with a state where the vehicle is stopped and the steering is not gripped.
That is, when the vehicle is in a traveling state and the steering is gripped, it is estimated that there is a high possibility of the gripped state being maintained thereafter. Accordingly, in such a case, the steering can be effectively warmed by expanding the interval of sensor driving and thus, extending the execution time of heater driving.
It is preferable that the steering device further includes a traveling state determination unit configured to determine a traveling state of a vehicle, and the interval of sensor driving is shortened in a state where the vehicle is in a traveling state and the steering is not gripped, compared with a state where the vehicle is stopped and the steering is not gripped.
That is, in a state where the steering is not gripped even though the vehicle is in the traveling state, it is estimated that there is a high possibility of the steering being gripped thereafter. Accordingly, in such a case, the gripped state of the steering can be determined with high accuracy by increasing the frequency at which sensor driving is executed.
It is preferable that the steering device further includes a steering state determination unit configured to determine a steered state of the steering on the basis of a steering angle of the steering, and the interval of sensor driving is expanded in a state where the steering is steered, compared with a state where the steering is not steered.
That is, when the steering is in a steered state, it is estimated that there is a high possibility of the steering being in a gripped state. Then, it is estimated that the gripped state of the steering being continued thereafter. Thus, in such a case, the steering can be effectively warmed by expanding the interval of sensor driving and thus, extending the execution time of heater driving.
In the steering device, it is preferable that the heater drive unit starts the heater driving when it is detected that the steering is in a gripped state.
According to the above configuration, the steering can be efficiently warmed and power saving thereof can be achieved.
In the steering device, it is preferable that an amount of energization current to the heater is changed in addition to changing the interval of sensor driving.
Thus, the heater can be optimally controlled according to the interval of sensor driving.
In the steering device, it is preferable that the amount of energization current to the heater is decreased when the interval of sensor driving is expanded.
Thus, an excessive increase in temperature can be prevented.
In the steering device, it is preferable that the amount of energization current to the heater is increased when the interval of sensor driving is expanded.
Thus, the steering can be rapidly warmed.
In the steering device, it is preferable that the amount of energization current to the heater is decreased when the interval of sensor driving is shortened.
Thus, further power saving can be achieved.
In the steering device, it is preferable that the amount of energization current to the heater is increased when the interval of sensor driving is shortened.
Thus, a reduction in temperature can be prevented.
In the steering device, it is preferable that the sensor element is a capacitance sensor.
That is, in a configuration using the capacitance sensor as the sensor element, for example, when heater driving and sensor driving are performed at the same time, there is a higher possibility of affecting detection of the gripped state of the steering. Accordingly, with the above configuration, the gripped state can be detected with high accuracy.
According to the aspects of this disclosure, it is possible to detect the gripped state by a driver while warming a steering more suitably.
The principles, preferred embodiment and mode of operation of the present invention have been described in the foregoing specification. However, the invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. Further, the embodiments described herein are to be regarded as illustrative rather than restrictive. Variations and changes may be made by others, and equivalents employed, without departing from the spirit of the present invention. Accordingly, it is expressly intended that all such variations, changes and equivalents which fall within the spirit and scope of the present invention as defined in the claims, be embraced thereby.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-215768 | Nov 2018 | JP | national |
