CN-122003353-A - Touch detection device

CN122003353ACN 122003353 ACN122003353 ACN 122003353ACN-122003353-A

Abstract

A touch detection device is provided. The touch detection device includes a steering body, a plurality of sensor units each generating an electrostatic capacitance between a sensor electrode disposed at an outer peripheral portion of a base of the steering body and an occupant in contact with the steering body, a detection unit detecting the electrostatic capacitance of each of the sensor electrodes, a correction unit correcting the electrostatic capacitance of each of the sensor electrodes detected in the detection unit using a difference representing a change in the electrostatic capacitance of each of the sensor electrodes detected in the detection unit, and a determination unit determining a contact state of the occupant with respect to the steering body based on the corrected electrostatic capacitance.

Inventors

NAIL
IKEYAMA MASAHIRO
SUN HANYU

Assignees

株式会社东海理化电机制作所

Dates

Publication Date: 20260508
Application Date: 20241115
Priority Date: 20231206

Claims (10)

1. A touch detection device, comprising: a steering body formed by covering a conductive core member grounded to a vehicle body with an insulating base, and steering the vehicle by being contacted and operated by an occupant; a plurality of sensor units that generate electrostatic capacitances between sensor electrodes respectively arranged at outer peripheral portions of the base body of the steering body and occupants contacting the steering body; A detection unit for detecting the capacitance of each of the sensor electrodes; a correction section that corrects the electrostatic capacitance of each of the sensor electrodes detected in the detection section using a difference value representing a change in the electrostatic capacitance of each of the sensor electrodes detected in the detection section, and And a determination unit that determines a contact state of the occupant with the steering body based on the corrected electrostatic capacitance.
2. The touch detection device of claim 1, wherein the touch detection device comprises a touch sensor, The sensor electrode is provided on one surface of the sheet-like insulating support body, and is opposed to the core member.
3. The touch detection device of claim 1, wherein the touch detection device comprises a touch sensor, The sensor electrodes are arranged in pairs on the left and right sides of the steering body in the vehicle width direction.
4. The touch detection device of claim 1, wherein the touch detection device comprises a touch sensor, The correction section includes setting a correction value for correcting the electrostatic capacitance of each of the sensor electrodes using an absolute value of the difference value of each of the sensor electrodes.
5. The touch detection device of claim 4, wherein the touch detection device comprises a touch sensor, Comprises a temperature detection part for detecting the change of the ambient temperature around the steering body, The correction section sets the correction value according to each of the difference values and the change in the ambient temperature.
6. The touch detection device of claim 4, wherein the touch detection device comprises a touch sensor, The correction portion includes a reference value setting portion that sets an initial value of a reference value of the electrostatic capacitance of each of the sensor electrodes in a state where an occupant does not contact the steering body, and updates and sets the reference values individually using the correction values, The correction unit corrects the capacitance of each sensor electrode using the reference value after the update setting is performed for each sensor electrode.
7. The touch detection device of claim 4, wherein the touch detection device comprises a touch sensor, The correction unit includes means for evaluating whether or not the correction value is smaller than a preset threshold value, and means for correcting the capacitance of each sensor electrode using the correction value when the evaluation is that the correction value is smaller than the threshold value.
8. The touch detection device of claim 7, wherein the touch detection device comprises a touch sensor, The steering device comprises a heating part which is arranged in the matrix in the steering body and heats the steering body through work.
9. The touch detection device of claim 8, wherein the touch detection device comprises a touch sensor, The threshold value is changed according to the operation state of the heating part.
10. The touch detection device of claim 9, wherein the touch detection device comprises a touch sensor, The threshold value is set to be higher when the heating unit is operated than when the heating unit is not operated.

Description

Touch detection device Technical Field The present disclosure relates to a touch detection device that detects contact of an occupant. Background Japanese patent application laid-open No. 2017-87883 discloses a contact determination processing device in which a shield layer is formed on the side of a core (and a heater layer) so as to surround the core for a contact sensor in which the output is changed according to a contact state in which an occupant touches a steering wheel and a non-contact state in which the occupant does not touch the steering wheel. In the contact determination processing device, the contact state is determined when the output of the contact sensor is equal to or greater than a predetermined threshold value, and the non-contact state is determined when the output is smaller than the predetermined threshold value. At this time, the contact determination processing device detects the steering wheel temperature, the ambient temperature, or the estimated temperature, and changes the threshold value according to the detected or estimated temperature. In the contact determination processing device, when the heater for heating the steering wheel is driven, the threshold value is lowered by a predetermined value until a predetermined time elapses or a predetermined temperature is reached after the heater is driven. In a vehicle, a structure for detecting a touch of a steering wheel by an occupant is desired to be low-cost, and in a steering wheel or a touch sensor, a structure can be simplified by eliminating a shield layer (shield electrode), and cost can be reduced. Further, the dielectric constant and the like of the insulating material interposed between the sensor electrode and the core rod and the heater are changed by the temperature. Therefore, when the shield electrode disposed on the core portion side of the sensor electrode is removed, there is a problem that the parasitic capacitance generated by the sensor electrode is changed due to a change in the temperature in the vehicle interior, and the detection accuracy of touch detection using the sensor electrode is lowered. Disclosure of Invention The present disclosure provides a touch detection device capable of suppressing a decrease in detection accuracy in touch detection that detects contact of an occupant with a steering wheel. The touch detection device according to claim 1 includes a steering body formed by covering a conductive core member grounded to a vehicle body with an insulating base body and steering the vehicle by being brought into contact with an occupant, a plurality of sensor portions for generating electrostatic capacitances between sensor electrodes respectively disposed on an outer peripheral portion of the base body of the steering body and the occupant in contact with the steering body, a detection portion for detecting the electrostatic capacitances of the sensor electrodes, a correction portion for correcting the electrostatic capacitance of each of the sensor electrodes detected by the detection portion by using a difference value indicating a change in the electrostatic capacitance of each of the sensor electrodes detected by the detection portion, and a determination portion for determining a contact state of the occupant with respect to the steering body based on the corrected electrostatic capacitances. In the touch detection device according to claim 2, in the touch detection device according to claim 1, the sensor electrode is provided on one surface of the sheet-like insulating support body, and is opposed to the core member. In the touch detection device according to claim 3, in the steering body according to claim 1 or 2, the sensor electrodes are arranged in pairs on the left and right sides in the vehicle width direction. In the touch detection device according to claim 4, in any one of claims 1 to 3, the correction unit includes a correction unit that sets a correction value for correcting the capacitance of each of the sensor electrodes by using an absolute value of the difference value of each of the sensor electrodes. The touch detection device according to claim 5 is the touch detection device according to claim 4, further comprising a temperature detection unit that detects a change in the ambient temperature around the steering body, wherein the correction unit sets the correction value based on the difference value and the change in the ambient temperature. In the touch detection device according to claim 6, the correction unit includes a reference value setting unit that sets an initial value of a reference value of the capacitance of each sensor electrode in a state where the occupant does not contact the steering body, updates the reference value using the correction value, and corrects the capacitance of each sensor electrode using the reference value updated and set for each sensor electrode, in accordance with the capacitance of each sensor electrode in the state where the occupa