JPH057536Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a steering angle detection device that can accurately detect the steering angle of a vehicle.

[Prior Art] In-vehicle navigation systems that estimate the current location of a vehicle and display it on a map projected on a display device inside the vehicle use radio waves from satellites, geomagnetism, etc. to determine the vehicle's direction of travel or current location. I'm trying to detect it. However, with in-vehicle navigation systems that utilize geomagnetism, the output of the geomagnetic sensor changes due to the influence of strong disturbance magnetic fields formed around elevated tracks, railroad crossings, etc. even when the vehicle's direction of travel is not actually changed. If this happens, there is a risk that the central processing unit will incorrectly estimate the vehicle's course. One way to avoid this type of misestimation is to
A method of checking whether the vehicle has actually changed course by detecting the rotation angle of the vehicle's steering wheel may also be used.

In the conventional steering angle detection device 1 shown in FIG. 2, a slit disk 4 is coaxially fixed to the shaft 3 of a steering wheel 2, and the rotation angle of the slit disk 4 is arranged so that the detection phases are different from each other by 90 degrees. A rotation direction determination circuit 7 detects the rotation direction by a pair of photo encoders 5 and 6 and determines the rotation direction by receiving outputs from both photo encoders 5 and 6, and one photo encoder 5
(or 6), the steering angle sensor 8
is configured to detect the steering angle.

[Problems to be solved by the invention] The conventional steering angle detection device 1 described above can detect the rotation angle and rotation direction of the steering wheel 2 with the precision of the photo encoders 5 and 6; 2 even if it moves slightly within the range of play, it will be detected as a change in the steering angle, so even if the vehicle is not actually changing course, it may be difficult to drive straight if there is strong vibration from the road surface or strong wind resistance. However, there are problems in that it is easy to obtain erroneous information such as whether a course change has been made even though the vehicle is in the same state, and this adversely affects course estimation by the on-vehicle navigation system.

[Means for solving the problem] This invention solves the above problem, and includes a rotation sensor that detects the rotation angle of the steering wheel, and a rotation sensor that detects the steering resistance when the steering wheel is rotated. and a steering angle sensor that captures the output of the rotation sensor and detects the steering angle of the vehicle only when the torque sensor detects steering resistance exceeding a certain value. It is.

[Function] This invention captures the output of the rotation sensor that detects the rotation angle of the steering wheel into the steering angle sensor only when the torque sensor detects steering resistance that exceeds a certain value. Make accurate judgments through operations.

[Example] Hereinafter, an example of this invention will be described with reference to FIG. FIG. 1 is a schematic diagram showing an embodiment of the steering angle detection device of this invention.

In FIG. 1, the steering angle detection device 11 includes a rotation sensor 12 that detects the rotation angle of the steering wheel 2.
and a torque sensor 13 that detects steering resistance when the steering wheel 2 is rotated.Only when this torque sensor 13 detects steering resistance that exceeds a certain value, the output of the rotation sensor 12 is taken in and the output of the rotation sensor 12 is detected. It is composed of a steering angle sensor 14 that detects the steering angle. The rotation sensor 12 is a slit disk 12a fixed to the shaft 3 of the steering wheel 2.
and a single photo encoder 12b that detects its rotation. The torque sensor 13 is constructed by inserting a pair of left and right sleeves 13a into two gripping portions divided into three parts by spokes 2a that support the steering wheel 2 at three points.
A pressure-sensitive sensor 13b is attached to each end of the sensor. Therefore, when the sleeve 13a is gripped and the steering wheel 2 is rotated left and right, the pressure sensor 13b at the tip in the rotation direction is pressed against the spokes 2a of the steering wheel 2.
Detect changes in pressure. This change in pressure is proportional to the steering resistance of the steering wheel 2,
It is possible to know the steering force along with the steering direction. As the pressure-sensitive sensor 13b, a conductive rubber material that detects pressure, a pressure-sensitive element that detects the pressure inside a gas-filled cell using a semiconductor strain gauge, or the like is used. The steering angle sensor 14 is the torque sensor 13
The steering wheel operates in response to a gate signal output when the steering wheel detects a steering force exceeding a certain value, and only at that time the steering angle is detected by taking in the output of the rotation sensor 12.

Assume that the steering wheel 2 is now rotated clockwise. At that time, it is assumed that the pressure sensor 13b at the tip in the rotational direction of the sleeve 13a constituting the torque sensor 13 detects a steering force exceeding a certain value. In this case, the pressure sensor 13b on the tip side in the rotational direction of the sleeve 13a detects the steering resistance, so that the steering force and the steering direction are simultaneously detected. Therefore, when the steering resistance detected by the pressure sensor 13b exceeds a predetermined constant value, the steering angle sensor 14 is switched to the operating state by the gate signal output from the torque sensor 13.
As a result, the output of the rotation sensor 12 is taken into the steering angle sensor 14 as a meaningful signal associated with steering, and is used for detecting the steering angle.

In this way, the steering angle detection device 11 transmits the output of the rotation sensor 12 that detects the rotation angle of the steering wheel 2 to the steering angle sensor 14 only when the torque sensor 13 detects steering resistance exceeding a certain value. Because of the configuration, the course of the vehicle can be accurately determined through the operation of the steering wheel 2, and the conventional steering angle detection device 1 detects the steering angle by looking only at the rotation of the steering wheel 2.
Unlike other systems, only the actually effective steering can be taken into account in determining the course, so even if the steering wheel 2 moves slightly within the range of play due to vibrations from the road surface or wind pressure, the vehicle will be accurately adjusted regardless of this. It is possible to determine the course of a geomagnetic sensor, especially when installed in an on-vehicle navigation device that uses geomagnetism, to strengthen the correction function when the geomagnetic sensor makes a wrong course judgment due to the influence of disturbance. can do.

[Effects of the invention] As explained above, this invention has a configuration in which the output of the rotation sensor that detects the rotation angle of the steering wheel is input to the steering angle sensor only when the torque sensor detects steering resistance exceeding a certain value. Because of this, the vehicle's course can be accurately determined through steering wheel operation, and unlike conventional steering angle detection devices that detect the steering angle by looking only at the rotation of the steering wheel, only the actually effective steering can be used to determine the course. Even if the steering wheel moves slightly within the range of play due to vibrations from the road surface or wind pressure, the vehicle's course can be determined accurately regardless of this, especially when using geomagnetism. When installed in a vehicle-mounted navigation system, etc., it has excellent effects such as strengthening the correction function when the geomagnetic sensor makes a wrong course judgment due to the influence of disturbance.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an embodiment of the steering angle detection device of this invention, and FIG. 2 is a schematic configuration diagram showing an example of a conventional steering angle detection device. 2... Steering wheel, 11... Rudder angle detection device, 12... Rotation sensor, 13... Torque sensor, 14... Rudder angle sensor.

Claims (1)

[Scope of utility model registration request] A rotation sensor detects the rotation angle of the steering wheel, a torque sensor detects the steering resistance when the steering wheel is rotated, and only when this torque sensor detects the steering resistance exceeding a certain value, the rotation A steering angle detection device that includes a steering angle sensor that captures the output of the sensor and detects the steering angle of the vehicle.