Patent Publication Number: US-2021163055-A1

Title: Steering, steering system, method for controlling steering, and non-temporary computer readable storage media

Description:
TECHNICAL FIELD 
     The present invention is related to steering, a steering system, a method for controlling steering, and non-temporary computer readable storage media. 
     BACKGROUND 
     Conventionally, heaters have been developed to heat steering wheels of automobiles for comfortable operation of the vehicle on cold days, such as in winter. For example, Patent Document  1  describes an automotive heating device that includes a heating element mounted to cover the steering wheel, a control circuit configured to control energization of the heating element, and a switch that outputs a signal to the control circuit. In this automotive heating device, energization to the heating element is initiated by the operation of the switch by the driver and stopped after a prescribed period of time. 
     Another conventionally known technology is providing a capacitive touch sensor on the steering wheel to detect whether or not the driver is grasping the steering wheel (for example, see Patent Document  2 ). 
     RELATED ART DOCUMENTS 
     Patent Documents 
     [Patent Document 1] Japanese Unexamined Patent Application H09-76922 
     [Patent Document 2] Japanese Unexamined Patent Application 2010-23699 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     However, there has not been sufficient consideration for installing a heater and a touch sensor together in a steering wheel conventionally, and this needs to be improved. 
     Therefore, an object of the present invention is to provide a steering device, a steering system, a method for controlling steering, and non-temporary computer readable storage media that are capable of adding a grasp detection function to a steering device with a heater function, of which one function can contribute to improving the other function. 
     Means for Solving the Problem 
     The steering wheel according to one embodiment of the present invention is a steering wheel provided with a core part to which a ground potential is supplied, provided with a first conductor insulated from the core part on the exterior of the core part for warming the steering wheel, and a second conductor insulated from the first conductor on the exterior of the first conductor for detecting grasping of the steering wheel. 
     The method of controlling the steering wheel according to one embodiment of the present invention is a method of controlling a steering wheel provided with a first conductor for warming the steering wheel and a second conductor insulated from the first conductor on the exterior of the first conductor, and includes a step of outputting a first control signal that controls the ON and OFF actions of a first switching part that switches an electrical connection between one end of the first conductor and a power supply, and a step in determining whether or not the steering wheel is being grasped by the driver based on capacitance measurement results of capacitive coupling produced between the second conductor and the grounding part. 
     The non-temporary computer readable storage media according to one embodiment of the present invention is a non-temporary computer readable storage media storing one or more programs that are configured to be executed by one or more processors of an electronic device and one or more programs that allow the electronic device to control the steering wheel, of which the steering wheel is provided with a first conductor for heating the steering wheel and a second conductor insulated from the first conductor on the exterior of the first conductor, wherein the one or more programs include a command to output a first control signal to control the ON and OFF actions of a first switching part to switch the electrical connection between one end of the first conductor and a power supply, and a command to determine whether or not the driver is grasping the steering wheel based on capacitance measurement results of capacitive coupling produced between the second conductor and the grounding part. 
     According to these embodiments, the first conductor for the heating function is protected by the second conductor for the grasp detection function, as the second conductor is provided on the exterior of the first conductor. Herewith, when the driver grasps the steering wheel, the first conductor is not directly grasped, such that increase in resistance of the first conductor over time due to wear can be suppressed. Therefore, both functions can be provided to the steering wheel while achieving a synergistic effect of the second conductor for grasp detection function improving the durability of the first conductor for heating function. 
     Note that “grasp” in these specifications is not limited to the driver grasping on the steering wheel tightly, and also includes a state in which the body of the driver touches a part of the steering wheel. 
     Effect of the Invention 
     With the steering wheel, steering system, method of controlling steering, and non-temporary computer readable storage media of the present invention, a grasp detection function can be applied to a steering wheel with a heating function, where one function can contribute to the improvement of the other function. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating a cross-sectional structure of a steering wheel according to embodiment 1. 
         FIG. 2  is a diagram illustrating a circuit configuration and system configuration of the steering system according to embodiment 1. 
         FIG. 3  is a block diagram illustrating the computer hardware configuration included with the steering system according to embodiment 1. 
         FIG. 4  is a flowchart illustrating a method of controlling the steering wheel according to embodiment 1. 
         FIG. 5  is a diagram illustrating a circuit configuration and system configuration of the steering system according to embodiment 2. 
         FIG. 6  is a timing chart of the steering system according to embodiment 2. 
         FIG. 7  is a diagram illustrating a circuit configuration and system configuration of the steering system according to embodiment 3. 
         FIG. 8  is a diagram illustrating a circuit configuration and system configuration of the steering system according to embodiment 4. 
     
    
    
     EMBODIMENT OF THE INVENTION 
     Embodiments of the present invention are described with reference to the accompanying diagrams below. In each diagram, the same reference numerals designate identical or similar configurations. In addition, in the second and subsequent embodiments, descriptions of items common to the first embodiment will be omitted, and only different points will be described. In particular, successive references are not made for similar effects of similar configurations for each embodiment. 
     1. Embodiment 1 
     The steering wheel  1  is an operating device for operating the driving of a vehicle, and has a heater function that warms the steering wheel itself, and a grasp detection function for detecting whether or not the steering wheel is grasped by the driver. As illustrated in  FIG. 1 , the steering wheel  1  includes, in order from the interior, a core metal  10 , a urethane layer  11 , a heater electrode  12 , an outer skin layer  13 , and a sensor electrode  14 . The core metal  10  is an example of a core part, and the heater electrode  12  and the sensor electrode  14  are respectively examples of a first conductor and a second conductor. 
     The core metal  10  makes up the framework portion of the steering wheel  1  and forms the shape of the steering wheel  1 . The core metal  10  is electrically connected to the grounding part of the vehicle where the steering wheel  1  is attached to the vehicle, and as such, the core metal  10  is at ground potential. In other words, ground potential is supplied to the core metal  10 . Note that the “grounding part” of the vehicle can be any location as long as the vehicle has a ground potential, and includes, for example, a vehicle body or the like. 
     The urethane layer  11  is provided covering the core metal  10  on the exterior (outer periphery in the present embodiment) of the core metal  10 , and insulates the core metal  10  and the heater electrode  12 . Note that the type of this insulation is not limited to the urethane layer  11 , and can be formed, for example, by using other materials other than urethane. 
     The heater electrode  12  is provided covering the urethane layer  11  on the exterior (outer periphery in the present embodiment) of the urethane layer  11 . The heater electrode  12  generates heat when supplied with power, thereby warming the steering wheel  1 . For example, the heater electrode  12  is formed by a planar heating element having a nichrome wire arranged in a planar shape. 
     The outer skin layer  13  is provided covering the heater electrode  12  on the exterior (outer periphery in the present embodiment) of the heater electrode  12 , and insulates the heater electrode  12  and the sensor electrode  14 . The material constituting the outer skin layer  13  is not particularly limited, and can be, for example, a leather conventionally used as an outer skin layer of steering wheels. 
     The sensor electrode  14  is provided covering the outer skin layer  13  on the exterior (outer periphery in the present embodiment) of the outer skin layer  13 . The sensor electrode  14  is an electrode for detecting by capacitive coupling whether or not the driver of the vehicle is grasping the steering wheel  1 . For example, the sensor electrode  14  is formed by spraying a conductive paint on the surface of the outer skin layer  13 . The function of detecting the grasping of the steering wheel  1  by the driver can be applied, for example, to a driving assistance system that assists the driver or to an alert system that alerts the driver. Note that the position where the sensor electrode  14  is provided need not necessarily be the outermost part of the steering wheel  1 , and the steering wheel  1  can have a non-conducting coating applied to a further exterior part of the sensor electrode  14 , for example. 
     Thus, regarding the steering wheel  1 , the heater electrode  12  and the sensor electrode  14  are formed so as to surround the core metal  10  in this order while the heater electrode  12  and the sensor electrode  14  are insulated from each other. In the example illustrated in  FIG. 1 , the heater electrode  12  and the sensor electrode  14  are formed over the entire circumference of the steering wheel  1 , in other embodiments however, the heater electrode  12  and the sensor electrode  14  need not be formed over the entirety of the steering wheel  1 . In other words, as long as a portion of the steering wheel  1  (for example, a portion that is easily grasped by the driver and the like) has the cross-sectional structure illustrated in  FIG. 1 , the heater electrode  12  and the sensor electrode  14  need not be formed on other portions. 
     As illustrated in  FIG. 2 , a steering system  100  includes, for example, the steering wheel  1 , a switching element  110 , a controller  120 , a heater power supply  130 , a capacitance measuring circuit  140 , and a grasp determining part  150 . The switching element  110 , controller  120 , capacitance measuring circuit  140 , and grasp determining part  150  are provided, for example, on an ECU (which is an example of an electronic device). In other embodiments, the switching element  110  and the capacitance measuring circuit  140  can be provided separately from the ECU and electrically connected to the ECU. Note that because both the urethane layer  11  and the outer skin layer  13  illustrated in  FIG. 1  are both included in the insulating layer in terms of the circuit configuration, the urethane layer  11  and the outer skin layer  13  are illustrated together as an insulating layer in  FIG. 2 . This is also true in  FIG. 5 ,  FIG. 7  and  FIG. 8 , which are shown below. 
     As illustrated in  FIG. 3 , an ECU  20  included in the steering system  100  includes a calculating part  21 , a communicating part  22 , an input/output part  23 , and a storage part  24 . 
     The calculating part  21  includes one or more processors and is made up of a CPU, an MPU, or the like. The calculating part  21  operates various functions by executing programs, modules, and/or instructions stored in the storage part  24  based on various inputs. Programs and the like can be installed from storage media such as a CD-ROM or USB memory or can be downloaded and installed via the communicating part  22 . The calculating part  21  includes, for example, the controller  120  and the grasp determining part  150 . The controller  120  outputs a control signal for controlling the switching element  110  ON and OFF, for example. The grasp determining part  150  determines whether or not the steering wheel  1  is grasped based on the capacitance value measured by the capacitance measuring circuit  140 , for example. 
     The communicating part  22  is an interface for connecting the ECU  20  to other devices. The communicating part  22  can be connected to a communication network such as the Internet, for example. The input/output part  23  receives data from other devices and outputs data to other devices. For example, the input/output part  23  is connected to the switching element  110 , and a control signal from the controller  120  is output to the switching element  110  via the input/output part  23 . Furthermore, for example, the input/output part  23  is connected to the capacitance measuring circuit  140 , and receives the measurement results of the capacitance measuring circuit  140 . 
     The storage part  24  is made up of a storage device such as a hard disk drive, an SSD, RAM, and ROM and the like. The storage part  24  stores various programs necessary to execute the calculation processes of the calculating part  21  and data necessary for the execution of various programs, and the like. Various programs include programs for controlling steering, for example. The storage part  24  includes non-volatile memory. Non-volatile memory includes non-temporary computer readable storage media. In addition, the storage part  24  stores the capacitance values measured by the capacitance measuring circuit  140 , and temporarily stores various types of information. 
     Returning to  FIG. 2 , the core metal  10  is electrically connected to the ground G of the vehicle, and the entire core metal  10  is set to ground potential. The heater electrode  12  is supplied with power from the heater power supply  130  via the switching element  110  at one end, and the other end is electrically connected to ground G. The sensor electrode  14  generates capacitive coupling with the driver while the driver is grasping the steering wheel  1 . Note that in  FIG. 2 , electrical connections by wiring are indicated by solid lines, and electrical connections based on capacitive coupling are indicated by dashed lines. 
     The switching element  110  (which is an example of a first switching part) switches the electrical connection between the heater electrode  12  and the heater power supply  130  by switching between ON and OFF based of the control signal Ctrl 1  (an example of the first control signal) supplied by the controller  120 . Specifically, when the switching element  110  is ON, power is supplied from the heater power supply  130  to the heater electrode  12 , and the heater electrode  12  generates heat. Meanwhile, when the switching element  110  is OFF, the supply of power from the heater power supply  130  to the heater electrode  12  is blocked, and heat generated by the heater electrode  12  is stopped. The switching element  110  can be a transistor such as a field-effect transistor (FET), for example, but is not limited thereto, and can be configured to switch an electrical connection in accordance with the control signal Ctrl 1 . 
     The controller  120  supplies the control signal Ctrl 1  to the switching element  110  to switch the switching element  110  ON and OFF. The controller  120  can receive an input of a switch operation by the driver of the vehicle, for example, and generate the control signal Ctrl 1  based on this input. The heater power supply  130  (an example of the power supply) supplies power to the heater electrode  12 . 
     The capacitance measuring circuit  140  supplies the capacitance measurement signal to the sensor electrode  14 , and measures a sum of the capacitance values of capacitive coupling that occurs between the sensor electrode  14  and each element that carries ground potential. Specifically, in a case where the driver does not grasp the steering wheel  1 , or in other words, when there is no capacitive coupling between the driver and the steering wheel  1 , the capacitance value Coff measured by the capacitance measuring circuit  140  is calculated by: the sum of the capacitance value Csa of the parasitic capacitance generated between the sensor electrode  14  and the core metal  10 , a capacitance value Csh of the parasitic capacitance generated between the sensor electrode  14  and the heater electrode  12 , and a capacitance value Csb of the parasitic capacitance generated between the sensor electrode  14  and the ground G of the vehicle. In other words, in this case, Coff=Csa+Csh+Csb. 
     Meanwhile, in a case where the driver grasps the steering wheel  1 , or in other words, when capacitive coupling is generated between the driver and the steering wheel  1 , the capacitance value Con measured by the capacitance measuring circuit  140  is calculated by: The capacitance values Csa, Csh, and Csb described above, and in addition, a capacitance value Ch of the capacitive coupling that occurs in the path from the sensor electrode  14  to the ground G of the vehicle via the human body of the driver. In other words, in this case, Con=Csa+Csh+Csb+Ch. Therefore, there will be a difference between the capacitance value Con when there is grasping of the steering wheel and the capacitance value Coff when there is no grasping, AC=Con−Coff=Ch. 
     The grasp determining part  150  determines whether or not the driver is grasping the steering wheel  1  based on the capacitance value measured by the capacitance measuring circuit  140 . Specifically, the grasp determining part  150  receives the capacitance value measured by the capacitance measuring circuit  140  intermittently at prescribed intervals, for example. Furthermore, when the capacitance value increases by greater than or equal to the prescribed threshold, the grasp determining part  150  determines that the steering wheel  1  has been grasped, and when the capacitance decreases by greater or equal to the prescribed threshold, the grasp determining part  150  determines that the steering wheel  1  has been released from grasp, and determines that the previous state is maintained if the capacitance value does not change at or more than the prescribed threshold value. 
     In reference to  FIG. 4 , the method of controlling the steering wheel  1  of the present embodiment will be described. The method can be performed by the ECU  20  described above. In this method, two steps are mainly performed in this method. 
     First, a control signal Ctrl 1  is output that controls the ON and OFF of the switching element  110  for switching the electrical connection between one end of the heater electrode  12  and the heater power supply  130  (step S 10 ). This is executed by the controller  120 . ON and OFF of the heater electrode  12  is controlled with this type of output step. 
     Second, in response to the measurement result of the capacitance value of the capacitive coupling generated between the sensor electrode  14  and ground G, a determination is made regarding whether or not the steering wheel  1  is being grasped by the driver based on the measured capacitance value (step S 20 ). This is performed by the grasp determining part  150 . As described above, the capacitance value is measured by the capacitance measuring circuit  140 . 
     With the steering wheel  1  of the present embodiment, both a heating function and a grasp detection function can be provided as the steering wheel  1  is provided with the heater electrode  12  and the sensor electrode  14 . In particular, the sensor electrode  14  is provided on the exterior of the heater electrode  12 , and thus the external part of the heater electrode  12  is protected by the sensor electrode  14 . As a result, durability of the heater electrode  12  can be improved. The following is a detailed description of this point. 
     In other words, the amount of heat Q generated by the heater electrode  12  is defined by Q=RI 2 , using the current rate I supplied to the heater electrode  12  and the resistance value R of the heater electrode  12 . Therefore, in order to obtain a sufficient amount of heat Q, the resistance value R of the heater electrode  12  is preferably low. Here, if the heater electrode  12  is provided on the exterior of the steering wheel  1 , the heater electrode  12  is grasped directly by the driver. As a result, the resistance value R of the heater electrode  12  may increase through degradation over time due to wear. In this regard, regarding the present embodiment, as the heater electrode  12  is arranged more to the inside than sensor electrode  14 , the wear described above can be suppressed, thus suppressing increase in the resistance value R. Therefore, durability of the heater electrode  12  can be improved. 
     However, since the sensor electrode  14  is grasped directly by the driver when grasping the steering wheel  1 , the resistance value can increase due to wear. However, as the resistance value between the sensor electrode  14  and the grounding part G is relatively large, even if the resistance value of the sensor electrode  14  is increased, the variation in the resistance value of the sensor electrode  14  relative to the resistance value between the sensor electrode  14  and ground G is relatively small. Therefore, wear of the sensor electrode  14  has a small effect on the measurement of the capacitance value by the capacitance measuring circuit  140 . In other words, by providing the sensor electrode  14  on the exterior of the heater electrode  12 , the grasp detection function can contribute to improving the durability of the heater function while adding the grasp detection function to the steering wheel with the heater function. 
     In other embodiments, switching ON and OFF the heater function (in other words, ON and OFF of the switching element  110 ) can be controlled, for example, based on the determination results from the grasp determining part  150 . For example, by controlling the heater function to turn ON upon detecting grasping on the steering wheel and to turn OFF the heater function upon detecting the grasping released, the steering wheel can be automatically warmed without interfering with the driving operation by the driver. 
     Here, regarding the steering system  100  provided with the heater function as described above, when the heater function is ON, the amount of current supplied to the heater electrode  12  is relatively high (for example, from a few to a few tens of Amps). Therefore, because the amount of current supplied to the heater electrode  12  suddenly fluctuates when turning ON and OFF the heater function, noise may be generated or the power supply voltage may fluctuate. Therefore, the following second embodiment will be described as a steering system that can suppress the effects of such noise and voltage fluctuations on peripheral circuits. 
     2. Embodiment 2 
     As illustrated in  FIG. 5 , a steering system  200  further includes a switching element  210  when compared with the steering system  100  described above. The switching element  210  (example of a second switching part) is provided in between the sensor electrode  14  and the ground G, and switches the electrical connection between the sensor electrode  14  and the ground G according to the control signal Ctrl 2  (example of a second control signal) supplied by the controller  120 . Similar to the switching element  110 , the switching element  210  can be a transistor such as a FET and the like, but is not limited thereto, as long as the electrical connections can be switched according to the control signal Ctrl 2 . 
     Regarding the present embodiment, the controller  120  outputs a control signal Ctrl 2  for switching the operation of the switching element  210  in accordance with the operation of the switching element  110 . Specifically, as illustrated in  FIG. 6 , the control signal Ctrl 2  is set to a high level that turns the switching element  210  ON when the switching element  110  is switched between ON and OFF, and the signal is set to a low level that turns the switching element  210  OFF when the switching element  110  is not switched ON or OFF for a prescribed amount of time. This turns the switching element  210  ON when switching the operation of the heater function, and the sensor electrode  14  becomes electrically connected to the ground G, such that the sensor electrode  14  is set to ground potential. Accordingly, even when noise or power supply voltage fluctuation occurs as the operation of the heater function is switched, the sensor electrode  14  functions as a shield, and the effects of these noise and voltage fluctuations can be suppressed. 
     Note that turning ON the switching element  210  is not limited to instances where the switching element  110  turns ON or OFF, but may include a time before and after the instance, as illustrated in  FIG. 6 . This allows for easier suppression of the effects of noise or the like associated with switching the operation of the heater function. 
     Additionally, regarding the present embodiment, the controller  120 , in addition to the control signal Ctrl 2 , outputs a control signal Ctrl 3  (example of a third control signal) indicating switching ON or OFF the switching element  110  and supplies this signal to the grasp determining part  150 . Specifically, similar to the control signal Ctrl 2 , the control signal Ctrl 3  is set to a high level when the switching element  110  is switched ON or OFF, and is set to a low level when the switching element  110  is not switched ON or OFF for a prescribed amount of time. When the control signal Ctrl 3  is at the high level, the grasp determining part  150  discards the measurement result of the capacitance from the capacitance measuring circuit  140 , and does not make a determination based on the capacitance (see arrow in  FIG. 6 ). In other words, while switching the operation of the heater function, fluctuations in the power supply voltage may occur, and the accuracy of the measurement of the capacitance value by the capacitance measuring circuit  140  can be reduced, so the measurement result of such a capacitance value is discarded (the output value is made invalid). As a result, the reliability of grasp determination of the grasp determining part  150  can be improved. 
     As described above, according to the steering system  200 , as a shielding function is added to the sensor electrode  14 , effects of noise and the like can be suppressed without the use of a separate shielding member. 
     Furthermore, as the presence or absence of grasp detection is controlled in response to switching the operation of the heater function, the reliability of the grasp detection function can be improved. 
     In another embodiment, the controller  120  may supply the capacitance measuring circuit  140  with the control signal Ctrl 3 , and when the control signal Ctrl 3  is at a high level, the capacitance measuring circuit  140  does not perform measurement of the capacitance value. In yet another embodiment, the control signal Ctrl 2  and the control signal Ctrl 3  can be output from differing controllers, instead of the one controller  120 . In a further different embodiment, the steering system  200  may include one of the functions, but not both of the functions, of the shielding function by the sensor electrode  14  and the function of discarding measurement results by the grasp determining part  150 . 
     Here, regarding the steering system  200  provided with a heater function as described above, a harness or the like that electrically connects the heater electrode  12  and the elements can be disconnected based on deterioration or breakdown. For example, when the connection between the other end of the heater electrode  12  and ground is blocked by a disconnection, parasitic capacitance between the sensor electrode  14  and the heater electrode  12  does not occur. As a result of the measurement result obtained by the capacitance measuring circuit  140  changing, there is a risk that the reliability of grasping determination by the grasp determining part  150  may be reduced. Accordingly, the following embodiments  3  and  4  will be described as a steering system that can resolve this point. 
     3. Embodiment 3 
     As illustrated in  FIG. 7 , a steering system  300  further includes a connection determining part  310  in comparison with the steering system  100  described above. The connection determining part  310  is provided between one end of the heater electrode  12  and the heater power supply  130 . The connection determining part  310  determines, for example, whether or not there is an electrical connection between the other end of the heater electrode  12  and the ground G (in other words, whether or not this connection is disconnected), and supplies a control signal Ctrl 4  (example of a fourth control signal) that indicates the results of this determination to the controller  120 . 
     When a disconnection occurs between the other end of the heater electrode  12  and the ground G, and the connection determining part  310  determines that there is no electrical connection therebetween, the controller  120  turns ON the switching element  110  based on the control signal Ctrl 4  supplied by the connection determining part  310 . This causes the heater electrode  12  to be short-circuited to the heater power supply  130 , creating a parasitic capacitance between the heater electrode  12  and the sensor electrode  14 . 
     According to the steering system  300  of the present embodiment, a parasitic capacitance can be generated between the sensor electrode  14  and the heater electrode  12  even if the electrical path including the heater electrode  12  is disconnected. Therefore, the reliability of the grasp detection function can be improved. 
     4. Embodiment 4 
     As illustrated in  FIG. 8 , a steering system  400  further includes a capacitor  410  in comparison with the steering system  100  described above. One end of the capacitor  410  is connected between one end of the heater electrode  12  and the heater power supply  130 , and the other end is electrically connected to ground G. The capacitance of the capacitor  410  is preferably greater than the capacitance Csh of the parasitic capacitance generated between the sensor electrode  14  and the heater electrode  12 , and can be, for example, 0.01 μF to 10 μF. Thus, the heater electrode  12  is put in a state equivalent to that of being shorted to the ground G. Thus, according to the steering system  400 , the parasitic capacitance between the sensor electrode  14  and the heater electrode  12  can be generated even when an electrical path including the heater electrode  12  is disconnected, similar to the steering system  300 . Therefore, the reliability of the grasp detection function can be improved. 
     Note that in  FIG. 8 , an example is illustrated in which one end of the capacitor  410  is connected between one end of the heater electrode  12  and the switching element  110 . However, the position at which one end of the capacitor  410  is connected is not limited thereto, and for example, can be between the switching element  110  and the heater power supply  130 . In  FIG. 8 , a configuration is illustrated in which the other end of the capacitor  410  is connected to the ground G, however, the connecting tip of the other end of the capacitor  410  is not limited thereto, and can be connected to the heater power supply  130 , for example. In this case, the heater electrode  12  is put in a state equivalent to that of being shorted to power supply voltage, which can also generate a parasitic capacitance between the sensor electrode  14  and the heater electrode  12 . 
     The embodiments described above are for ease of understanding of the present invention and are not intended to be construed as limiting the present invention. Each element included in each embodiment, as well as the arrangement, materials, conditions, shape, and size thereof, is not limited to those illustrated, but rather can be appropriately changed. In addition, the configurations shown in the various embodiments can be partially replaced or combined with each other. 
     For example, the device to which the heater function and the grasp detection function are applied is not limited to a steering wheel, and can be applied to other devices such as a shift lever of a vehicle and the like. 
     EXPLANATION OF CODES 
       1 . Steering;  10 . Core metal;  11 . Urethane layer;  12 . Heater electrode;  13 . Epidermal layer;  14 . Sensor electrode;  20 . ECU;  21 . Calculating part;  22 . Communication part;  23 . Input/output part;  24 . Storage part;  100 ,  200 ,  300 ,  400 . Steering system;  110 . Switch element;  120 . Controlling part;  130 . Heater power supply;  140 . Capacitance measuring circuit;  150 . Grip determining part;  210 . Switch element;  310 . Connection determining part;  410 . Capacitor