Navigation device and manufacturing method thereof

Abstract

The navigation device (91) includes a housing panel (11) and an inertial sensor (31). The housing panel (11) has a pair of side plates (11a) separated and opposed in a first direction. A pair of fixing portions (K) are provided on the pair of side plates (11a). The pair of fixing portions K are fixed to a moving body side fixing member (71). The inertial sensor (31) is provided inside the housing surrounded by the housing panel (11) and is disposed at a position sandwiched between the pair of fixing portions (K) in the first direction.

Description

Technical Field

[0001] The present disclosure relates to a navigation device including an inertial sensor and a method for manufacturing the navigation device. Background Art

[0002] A vehicle navigation device including an inertial sensor is described in Patent Document 1.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2011-169593. Summary of the Invention

[0006] Ideally, the inertial sensor mounted on the navigation device performs the same operation as the operation of a moving body such as a vehicle on which the navigation device is mounted. In the conventional vehicle navigation device, the installation position of the inertial sensor relative to the fixed position of the vehicle-side component is not considered. Therefore, when the installation position of the inertial sensor is far from the fixed position, etc., due to the deformation or vibration generated in the vehicle navigation device by the force or vibration received from the outside, the deviation between the operation of the inertial sensor and the operation of the vehicle sometimes becomes large. As a result, the position of the vehicle on which the vehicle navigation device is mounted sometimes cannot be detected with high accuracy.

[0007] An object of one or more embodiments is to provide a navigation device and a method for manufacturing the navigation device, which can improve the detection accuracy of the position of a moving body.

[0008] According to a first aspect of one or more embodiments, there is provided a navigation device including: a housing panel having a pair of side plates separated and opposed to each other in a first direction; a pair of fixing portions provided on the pair of side plates and fixed to a moving body side fixing member; and an inertial sensor provided inside the housing panel and disposed at a position sandwiched between the pair of fixing portions in the first direction.

[0009] According to a second aspect of one or more embodiments, a method for manufacturing a navigation device is provided, including: a pair of side plates of a housing panel in the navigation device are separated in a first direction and opposed to each other in parallel, the pair of side plates having a pair of fixing portions fixed to a vehicle-side fixing member, when viewed from the first direction, at a position between the pair of side plates that does not correspond to the position of the pair of fixing portions, a flat chassis is arranged in a posture orthogonal to the pair of side plates, a sensor substrate on which an inertial sensor is mounted is mounted on a bracket having a specified shape, and the bracket is fixed to a portion of the chassis where the amplitude during vibration applied to the navigation device is smaller than that of other portions, so as to arrange the inertial sensor at a position sandwiched between the pair of fixing portions in the first direction.

[0010] According to the navigation device and the method for manufacturing the navigation device according to one or more embodiments, the detection accuracy of the position of the moving body can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 FIG. 9 is an assembled perspective view showing a navigation device 91 and its mounting structure as a navigation device according to one or more embodiments.

[0012] Figure 2 FIG. 13 is a left view showing the mounting posture of the navigation device 91.

[0013] Figure 3 FIG. 17 is a perspective view showing a chassis 22 and a bracket 23 included in the navigation device 91.

[0014] Figure 4 FIG. Figure 3 is a cross-sectional view taken at positions S4A - S4A and S4B - S4B in FIG.

[0015] Figure 5 FIG. 27 is an exploded perspective view including a simulation result of the amplitude response of the chassis 22 to external vibration.

[0016] Figure 6 FIG. 31 is a first schematic diagram for explaining a setting range of the center of gravity position G31 of an inertial sensor 31 in the navigation device 91.

[0017] Figure 7 FIG. 35 is a second schematic diagram for explaining a setting range of the center of gravity position P31.

[0018] Figure 8 FIG. 39 is a third schematic diagram for explaining a setting range of the center of gravity position P31. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] With Figure 1Taking the navigation device 91 shown as an example, the navigation device related to one or more embodiments will be described. Figure 1 It is a three-dimensional assembly view showing the mounting structure in which the navigation device 91 is mounted on the vehicle-side fixing member 71 as a moving body-side fixing member. For ease of explanation, Figure 1 The directions of up, down, left, right, front, and back in the navigation device 91 are defined by the directions of the arrows shown. In addition, the axis extending in the left-right direction is called the X-axis, the axis extending in the front-back direction is called the Y-axis, and the axis extending in the up-down direction is called the Z-axis. Sometimes the extending direction of the X-axis is called the first direction.

[0020] The navigation device 91 is mounted on a moving body such as a vehicle, an aircraft, or a ship. The navigation device 91 in the following description is an in-vehicle navigation device mounted on a vehicle.

[0021] As Figure 1 shown, the navigation device 91 has a substantially hexahedral main body 1 in appearance. The main body 1 has a front panel portion 12 at the front, and the upper part and the left and right side parts are covered by the outer shell panel 11. The front panel portion 12 has an image display portion 13 for displaying an image. The outer shell panel 11 has an upper top plate 11b and a pair of left and right side plates 11a. The pair of side plates 11a are spaced apart in the left-right direction and are opposed to each other in parallel.

[0022] Each side plate 11a has a fixing portion K capable of screwing an external thread on the front side. In this example, as the fixing portion K, a plurality (4 in this example) of fixing portions 11a1 to 11a4 are provided. The fixing portions 11a1 to 11a4 are provided at symmetric positions in the left and right side plates 11a.

[0023] In each side plate 11a, the fixing portions 11a1 to 11a4 are arranged at the vertex positions of a rectangle Ra extending in the up-down, front-back, and left-right directions along each edge. Specifically, the fixing portion 11a1 is located at the front lower position, the fixing portion 11a2 is located at the rear lower position, the fixing portion 11a3 is located at the front upper position, and the fixing portion 11a4 is located at the rear upper position. In this way, when the four fixing portions 11a1 to 11a4 are located at the vertices of a quadrilateral, the imaginary axis extending in the left-right direction passing through the diagonal center position of the quadrilateral is set as the fixing axis CL1.

[0024] Inside the front part of the main body 1, a sensor substrate 21 on which an inertial sensor 31 is mounted is arranged. The inertial sensor 31 is arranged at a position sandwiched between a pair of fixing portions K. On the inertial sensor 31, detection reference axes 31X, 31Y, and 31Z as orthogonal three axes are set. The inertial sensor 31 is a six-axis sensor that detects the acceleration in each axis direction and the angular acceleration around each axis.

[0025] The vehicle-side fixing member 71 is, for example, a pair of members separated left and right provided in the instrument panel of the vehicle. The pair of vehicle-side fixing members 71 are separated and arranged at intervals substantially in contact with the pair of side plates 11a of the navigation device 91. The vehicle-side fixing member 71 has four through holes 71a corresponding to the fixing portions 11a1 to 11a4 in the side plate 11a of the navigation device 91, respectively.

[0026] In this structure, the navigation device 91 is fixed to the vehicle-side fixing member 71 by passing the fixing screw N1 through the through hole 71a of the vehicle-side fixing member 71 and screwing it with the fixing portions 11a1 to 11a4 of the navigation device 91. Hereinafter, the posture of the navigation device 91 in the state where the navigation device 91 is fixed to the vehicle-side fixing member 71 is referred to as the installation posture.

[0027] Figure 2 is a left view of the navigation device 91 in the installation posture. As Figure 2 shown, the gravity direction is set as the vertical axis V (vertical axis), the axis in the front-rear direction perpendicular to the vertical axis V is set as the horizontal axis H (horizontal front-rear axis), and the axis in the left-right direction ( Figure 2 the front-back direction of the paper surface) perpendicular to the vertical axis V is set as the horizontal left-right axis LR. The X axis of the navigation device 91 in the installation posture coincides with the horizontal left-right axis LR, and the Y axis and the Z axis are respectively set to the directions rotated clockwise by an angle θa around Figure 2 the horizontal axis H and the vertical axis V. That is, in the installation posture, the navigation device 91 has an inclined posture in which the front side is inclined upward by an angle θa with respect to the horizontal direction.

[0028] As Figure 2 shown, a chassis 22 and a bracket 23 are provided inside the main body 1 of the navigation device 91. The chassis 22 is arranged above the center line CL91 in the vertical direction of the navigation device 91 and parallel to the top plate 11b. When viewed from the X-axis direction, the chassis 22 is arranged at a position not corresponding to the position of the fixing portion K, in other words, at a position away from the fixing portion K. The bracket 23 is fixed to the chassis 22 and supports the sensor substrate 21 so that the sensor substrate 21 is located below the chassis 22.

[0029] In the installation posture, the inertial sensor 31 is arranged at a position intersecting the fixed axis CL1. For example, the inertial sensor 31 is arranged so that the detection reference axis 31X coincides with the fixed axis CL1.

[0030] Figure 3 is a perspective view showing the mounting manner of the chassis 22, the bracket 23, the sensor substrate 21, and the inertial sensor 31. Figure 4 is showing Figure 3 the cross sections at the S4A - S4A position and the S4B - S4B position in Figure 5It is a three-dimensional exploded perspective view showing the mounting method of the bracket 23 and the sensor substrate 21 relative to the chassis 22. Figure 3 and Figure 5 It is a three-dimensional view of observing this part obliquely from the lower right rear, and is shown as being upside down with the upper side of the paper surface becoming the lower side of the Z axis. Figure 4 It is a cross-sectional view observed from the left side, and is shown as being upside down with the upper side of the paper surface becoming the lower side of the Z axis. Additionally, Figure 5 It also shows regions M1 and M2 (to be described in detail later), which are the simulation results of the amplitude response of the chassis 22 to external vibrations.

[0031] As Figure 3 and Figure 5 shown, the chassis 22 is made of metal and is formed into a substantially rectangular plate shape. The chassis 22 has a plurality of fixing portions 221, and the plurality of fixing portions 221 are formed by cutting and lifting in order to be fixed to the top plate 11b of the outer shell panel 11 by screws. In this example, the chassis 22 has a pair of fixing portions 221L and 221R separated in the left-right direction at the front portion, and a pair of fixing portions 221 separated in the left-right direction at the rear portion. The chassis 22 is fixed to the outer shell panel 11 by fastening each fixing portion 221 to an unillustrated internal thread portion formed on the top plate 11b with fixing screws N2.

[0032] On the other hand, the bracket 23 is formed of a metal plate and has a base portion 23a, a protruding portion 23b, a pair of inclined connecting portions 23c, and a pair of seat portions 23d. The base portion 23a is an elongated plate-shaped portion extending in the left-right direction. The protruding portion 23b is a rectangular plate-shaped portion that protrudes obliquely upward and backward at the center portion in the left-right direction of the base portion 23a. The inclined connecting portions 23c are portions that extend obliquely upward and outward from both left and right ends of the base portion 23a and connect the base portion 23a and the seat portions 23d. The seat portions 23d are plate-shaped portions that extend parallel to the base portion 23a from the tips of the inclined connecting portions 23c and have through holes 23d1 (refer to Figure 5 ), and the threaded portions of the fixing screws N3 can be inserted through the through holes 23d1. The upper surfaces of the pair of seat portions 23d are included in the same imaginary plane. The base portion 23a is connected to the pair of seat portions 23d and the inclined connecting portions 23c.

[0033] If the inclined connecting portions 23c and the seat portions 23d as a whole are regarded as feet, the base portion 23a connects the pair of feet. The pair of feet are mounted at positions separated in the X-axis direction of the chassis 22.

[0034] On the lower surface of the protruding portion 23b, the sensor substrate 21 is fixed by screws with fixing screws N4. An inertial sensor 31 is mounted on the lower surface of the sensor substrate 21.

[0035] A pair of seat portions 23d of the bracket 23 are respectively fixed to fixing positions Q1 and Q2 (see Figure 5 ) near a pair of front corner portions among the four corners of the chassis 22 by fixing screws N3. In addition, near a pair of front corner portions of the chassis 22, as described above, left and right separated fixing portions 221L and 221R are arranged and fixed to the top plate 11b. Therefore, the fixing positions Q1 and Q2 become portions with higher rigidity than the central portion of the chassis 22.

[0036] As Figure 3 and Figure 4 shown, the sensor substrate 21 is fixed to the bracket 23, and the bracket 23 is mounted on the chassis 22. In this state, among the detection reference axes 31X, 31Y, and 31Z of the inertial sensor 31, the detection reference axis 31X coincides with the fixed axis CL1 of the navigation device 91 as described above. In addition, the detection reference axis 31Y extends parallel to the horizontal axis H, and the detection reference axis 31Z extends parallel to the Z axis.

[0037] Next, with reference to Figure 6 the installation position of the inertial sensor 31 in the above structure will be described in detail. Figure 6 is a diagram showing the positional relationship between the inertial sensor 31 and the fixing portions 11a1 to 11a4 in the installation posture of the navigation device 91, and is a schematic view observed from the left side of the fixed axis CL1.

[0038] As Figure 6 shown, the inertial sensor 31 is set such that the center of gravity position G31 coincides with the position of the fixed axis CL1. In the navigation device 91, this center of gravity position G31 is not limited to coinciding with the fixed axis CL1, and may be set within the range AR1.

[0039] The range AR1 is a rectangular range surrounded by a range ARh in the horizontal direction (the horizontal axis H direction) and a range ARv in the vertical direction (the vertical axis V direction). Specifically, the range ARh in the horizontal direction is the range between the center of the fixing portion 11a1 at the foremost position in the horizontal axis H direction and the center of the fixing portion 11a4 at the rearmost position among the four fixing portions 11a1 to 11a4. The range ARv in the vertical direction is the range between the center of the fixing portion 11a3 at the uppermost position in the vertical axis V direction and the center of the fixing portion 11a2 at the lowermost position.

[0040] When an external force or vibration in a certain direction is applied to the navigation device 91, substantially no bending or torsional deformation about the horizontal axis H and the vertical axis V occurs in the portion inside the range AR1 of the side plate 11a and the vehicle-side fixing member 71. Therefore, if the center-of-gravity position G31 is within the range AR1, the navigation device 91 can suppress the deviation between the operation of the inertial sensor 31 and the operation of the vehicle, and can detect the position of the host vehicle with higher accuracy compared to the case where the center-of-gravity position G31 is outside the range AR1. Thus, the navigation device 91 improves the detection accuracy of the position of the host vehicle.

[0041] In addition, the center-of-gravity position G31 is more preferably within a narrower range AR1a included in the range AR1. The range AR1a is a quadrilateral range obtained by connecting the center positions of the fixing portions 11a1 to 11a4 with line segments.

[0042] When an external force or vibration in a certain direction is applied to the navigation device 91, sometimes the entire side plate 11a and the vehicle-side fixing member 71 are deformed so as to be inclined with respect to the horizontal axis H and the vertical axis V, for example, about an axis such as the Y axis or the Z axis. Even in such a case, the portion inside the range AR1a in the side plate 11a and the vehicle-side fixing member 71 is not affected by this deformation. Therefore, if the center-of-gravity position G31 is within the range AR1a, the navigation device 91 can further suppress the deviation between the operation of the inertial sensor 31 and the operation of the vehicle, and can detect the position of the host vehicle with higher accuracy compared to when the center-of-gravity position G31 is within the range AR1. Thus, the navigation device 91 further improves the detection accuracy of the position of the host vehicle.

[0043] In addition, as a simulation of the response when vibration is applied from the outside, the amplitude distribution of the chassis 22 when the vehicle-side fixing member 71 is vibrated in a random vibration direction in the installation posture is obtained. In Figure 5 shows the result of classifying the obtained amplitude distribution into three levels of small, medium, and large according to the magnitude of the amplitude. That is, the region M2 marked with cross hatching is the region with a large amplitude, and the region M1 marked with single hatching is the region with a medium amplitude. The region M2 is located inside the region M1. The region outside the region M2 and the region M1 where no hatching is marked is the region with a small amplitude. The regions M1 and M2 can be considered as regions that resonate with the vibration applied from the outside.

[0044] As Figure 5As shown, regions M1 and M2 extend in the left-right direction and are distributed in the central portion in the left-right direction at the front in the chassis 22. If the bracket 23 is fixed in these regions M1 and M2, it can be predicted that the resonance of the chassis 22 will have a great influence on the operation of the inertial sensor 31. Therefore, in the navigation device 91, the bracket 23 is fixed at a position where the amplitude of the chassis 22 is small. Specifically, in the chassis 22, fixing positions Q1 and Q2 are selected that roughly correspond to region M1 in the front-rear direction and are respectively on the outer sides of region M1 in the left-right direction, and the bracket 23 is fixed at the fixing positions Q1 and Q2.

[0045] In this way, the bracket 23 is fixed to the chassis 22 at the fixing positions Q1 and Q2. Therefore, compared with the case where the bracket 23 is fixed to region M1 or M2 of the chassis 22, even when an external force such as external vibration is applied, the inertial sensor 31 is less likely to be affected by excessive vibration caused by the resonance of the chassis 22. That is, the inertial sensor 31 on the sensor substrate 21 fixed to the bracket 23 is less likely to vibrate excessively even when the main body 1 vibrates. Thus, the navigation device 91 can accurately detect the position of the vehicle itself even when an external vibration is applied.

[0046] The navigation device 91 with the above structure is manufactured by the following method. First, the navigation device 91 has a pair of side plates 11a that are separated in the X-axis direction, which is the first direction, and are opposed to each other in parallel. In addition, the navigation device 91 includes a housing panel 11, and the housing panel 11 has fixing portions K (11a1 to 11a4) fixed to the vehicle-side fixing member 71 on the pair of side plates 11a. The fixing portions K fix the housing panel 11 to a pair of vehicle-side fixing members 71 located on the two outer sides of the pair of side plates 11a using fixing screws N1.

[0047] As a manufacturing method, when viewed from the X-axis direction, a flat chassis 22 is arranged in a posture orthogonal to the side plates 11a at a position that does not correspond to the positions of the fixing portions 11a1 to 11a4 between the pair of side plates 11a. That is, when viewed from the X-axis direction, the chassis 22 is arranged at a position offset from the fixing portions 11a1 to 11a4.

[0048] In addition, the sensor substrate 21 equipped with the inertial sensor 31 is mounted on a bracket 23 with a specified shape. The bracket 23 is fixed to the chassis 22 at a position where the amplitude of vibration applied to the navigation device 91 is smaller than that of other parts. When viewed from the X-axis direction, the inertial sensor 31 is arranged at a position sandwiched between a pair of fixing parts K. Preferably, the inertial sensor 31 is arranged at a position corresponding to the position of the fixing part K when viewed from the X-axis direction. The state where the inertial sensor 31 is located at a position corresponding to the position of the fixing part K when viewed from the X-axis direction means that the inertial sensor 31 is located at a position overlapping the fixing part K when viewed from the X-axis direction. At this time, the positions of the Y-axis and Z-axis directions of the inertial sensor 31 are substantially the same as those of the Y-axis and Z-axis directions of the fixing part K.

[0049] The so-called other parts in the chassis 22 refer to the regions M1 and M2 where relatively large amplitudes are generated due to resonance when vibration is applied to the navigation device 91.

[0050] The present invention is not limited to the one or more embodiments described above, and various modifications can be made without departing from the gist of the present invention.

[0051] The number of the fixing parts K is not limited to the above-mentioned four. For example, it can also be two or three.

[0052] As Figure 7 shown, when the fixing part K is composed of two fixing parts α1 and α2, the center-of-gravity position G31 of the inertial sensor 31 only needs to be set within the range AR2. The range AR2 is a range surrounded by the horizontal direction (horizontal axis H direction) range ARh2 and the vertical direction (vertical axis V direction) range ARv2. Specifically, the horizontal direction range ARh2 is the range between the centers of the fixing part α1 at the foremost position and the fixing part α2 at the rearmost position in the horizontal axis H direction among the two fixing parts α1 and α2. The vertical direction range ARv2 is the range between the centers of the fixing part α2 at the uppermost position and the fixing part α1 at the lowermost position in the vertical axis V direction.

[0053] In addition, as Figure 8As shown, when the fixing part K is composed of three fixing parts β1 to β3, the center of gravity position G31 of the inertial sensor 31 only needs to be set within the range AR3. The range AR3 is a range surrounded by the range ARh3 in the horizontal direction (the direction of the horizontal axis H) and the range ARv3 in the vertical direction (the direction of the vertical axis V). Specifically, the range ARh3 in the horizontal direction is the range between the center of the fixing part β1 at the foremost position in the horizontal axis H direction among the three fixing parts β1 to β3 and the fixing part β2 at the rearmost position. The range ARv3 in the vertical direction is the range between the center of the fixing part β3 at the uppermost position in the vertical axis V direction and the fixing part β2 at the lowermost position.

[0054] When an external force or vibration in one direction is applied to the navigation device 91, bending or torsional deformation around the horizontal axis H and around the vertical axis V substantially does not occur in the parts inside the respective ranges AR2 or AR3 in the side plate 11a and the vehicle-side fixing member 71. Therefore, if the center of gravity position G31 is within the range AR2 or AR3, the deviation between the operation of the inertial sensor 31 and the operation of the vehicle can be suppressed, and the vehicle position can be detected with higher accuracy compared to the case where the center of gravity position G31 is outside the ranges AR2 and AR3. Thus, even if the fixing part K is two or three, the navigation device 91 can improve the detection accuracy of the vehicle position.

[0055] When the fixing part K is two, the center of gravity position G31 is more preferably located Figure 7 on the line segment LN1 connecting the connecting fixing part α1 and the fixing part α2 as shown. When the fixing part K is three, the center of gravity position G31 is more preferably located Figure 8 within the range AR3a as shown. The range AR3a is the range of a triangle formed by connecting the center positions of the fixing parts β1 to β3 with line segments.

[0056] When an external force or vibration in one direction is applied to the navigation device 91, deformation such as tilting of the side plate 11a and the vehicle-side fixing member 71 as a whole with respect to the horizontal axis H and the vertical axis V around an axis such as the Y axis or Z axis sometimes occurs. Even in this case, the parts on the line segment LN1 and inside the range AR3a of the side plate 11a and the vehicle-side fixing member 71 are not affected by the deformation. Therefore, if the center of gravity position G31 is on the line segment LN1 or within the range AR3a, the navigation device 91 can further suppress the deviation between the operation of the inertial sensor 31 and the operation of the vehicle, and the vehicle position can be detected with higher accuracy compared to the case where the center of gravity position G31 is within the range AR2 or AR3. Thus, the navigation device 91 further improves the detection accuracy of the vehicle position.

[0057] The inertial sensor 31 is not limited to the substrate-mounted type. The inertial sensor 31 can be directly mounted on the base 23a of the bracket 23. That is, the inertial sensor 31 can be indirectly mounted on the base 23a of the bracket 23 via other components such as the sensor substrate 21, or can be directly mounted on the base 23a.

[0058] The navigation device 91 is also mounted on other moving bodies other than the vehicle. When mounted on other than the vehicle, the vehicle in the above description can be entirely replaced with a moving body.

[0059] This application claims priority based on Japanese Patent Application Nos. 2020-033583 and 2020-033587 filed with the Japan Patent Office on February 28, 2020, the entire disclosures of which are incorporated herein by reference.

Claims

1. A navigation device, comprising: a housing panel having a pair of side plates separated and opposed in a first direction; a pair of fixing parts provided on the pair of side plates and fixed to a moving body side fixing member; a chassis, when viewed from the first direction, disposed at a position between the pair of side plates that does not correspond to the positions of the pair of fixing parts, in a posture orthogonal to the pair of side plates; a bracket fixed to a portion of the chassis where the amplitude is smaller than that of other portions when the navigation device is subjected to vibration, and an inertial sensor provided inside the housing panel and disposed at a position between the pair of fixing parts in the first direction and mounted on the bracket.

2. The navigation device according to claim 1, wherein the pair of side plates are opposed in parallel, the bracket has a pair of legs and a base, the pair of legs are mounted at positions separated in the first direction in the chassis, the base connects the pair of legs, and the inertial sensor is directly or indirectly mounted on the base of the bracket.

3. The navigation device according to claim 2, wherein when viewed from the first direction, the chassis is disposed at a position that does not correspond to the positions of the fixing parts.

4. The navigation device according to any one of claims 1 to 3, wherein when viewed from the first direction, the inertial sensor is disposed at a position corresponding to the positions of the fixing parts.

5. A manufacturing method of a navigation device, comprising: a pair of side plates of a housing panel in the navigation device are separated and opposed in parallel in a first direction, the pair of side plates have a pair of fixing parts fixed to a vehicle side fixing member, when viewed from the first direction, a flat chassis is disposed at a position between the pair of side plates that does not correspond to the positions of the pair of fixing parts, in a posture orthogonal to the pair of side plates, mounting a sensor substrate on which an inertial sensor is mounted on a bracket having a specified shape, fixing the bracket to a portion of the chassis where the amplitude is smaller than that of other portions when the navigation device is subjected to vibration, thereby disposing the inertial sensor at a position between the pair of fixing parts in the first direction.

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