CN215503051U - Driver hands-off and health detection device, steering wheel and protective sleeve - Google Patents
Driver hands-off and health detection device, steering wheel and protective sleeve Download PDFInfo
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- CN215503051U CN215503051U CN202121014207.6U CN202121014207U CN215503051U CN 215503051 U CN215503051 U CN 215503051U CN 202121014207 U CN202121014207 U CN 202121014207U CN 215503051 U CN215503051 U CN 215503051U
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Abstract
The application provides a driver takes off one's hand and health detection device, steering wheel and protective sheath, the device includes: the device comprises a detection electrode, a load detection module, a bioelectricity detection module and a comprehensive processing module; the load detection module is connected with the detection electrodes and is used for acquiring the induction parameters of at least one detection electrode; the bioelectricity detection module is connected with at least two detection electrodes and is used for acquiring bioelectricity signals of a detection target through the at least two detection electrodes; the comprehensive processing module is connected with the load detection module and the bioelectricity detection module and is used for detecting the health state and/or the hands-off detection result of the detection target according to the induction parameters and the bioelectricity signals; therefore, the same electrodes are multiplexed, so that hands-off detection and health monitoring of the driver can be completed while the electrodes are not interfered with each other.
Description
Technical Field
The utility model relates to the technical field of automobiles, in particular to a device for detecting the hands-off and health of a driver, a steering wheel and a protective sleeve.
Background
With the concern of people on health, health monitoring is integrated into daily life, various devices gradually increase the health monitoring function, and an automobile is used as a tool which is more and more popularized to use, and the health monitoring function is also gradually increased, so that health data collection and real-time monitoring of a driver in the driving process can be realized; and in order to ensure driving safety, Hands-off detection (HOD) is becoming an essential configuration item for high-end vehicles, which is especially important for driver assistance systems, because the driving task is still performed by the driver today, and the Hands must be left on the steering wheel, and the state of the Hands on or off the steering wheel can be monitored by Hands-off detection technology, but at present, there is no solution that supports Hands-off detection and health monitoring at the same time.
Therefore, how to simultaneously realize the hands-off detection and the health monitoring of the driver is a problem to be solved urgently at present.
SUMMERY OF THE UTILITY MODEL
To the not enough that exists among the prior art, the driver that this application provided takes off the hand and health detection device, steering wheel and protective sheath, it has solved the problem that can't realize the driver simultaneously and take off the hand detection and health monitoring among the prior art.
In a first aspect, the present application provides a driver hands-off and health detection apparatus, the detection apparatus comprising: the device comprises a detection electrode, a load detection module, a bioelectricity detection module and a comprehensive processing module; the load detection module is connected with the detection electrodes and is used for acquiring the induction parameters of at least one detection electrode; the bioelectricity detection module is connected with the at least two detection electrodes and is used for acquiring bioelectricity signals of a detection target through the at least two detection electrodes; the comprehensive processing module is connected with the load detection module and the bioelectricity detection module and is used for detecting the health state and/or the hands-off detection result of the detection target according to the sensing parameters and the bioelectricity signals.
Optionally, the detection apparatus further comprises: the first end of the bioelectricity switching module is connected with the input end of the bioelectricity detection module, and the second end of the bioelectricity switching module and the third end of the bioelectricity switching module are switched between the output ends of the at least two detection electrodes and used for selecting two target electrodes to be connected with the bioelectricity detection module.
Optionally, the load detection module includes: a capacitance detection module or an impedance detection module.
Optionally, the capacitance detection module includes: the first end of the first resistor is connected with the output end of the electrode; a first end of the second resistor is connected with a second end of the first resistor; the output end of the first microcontroller is connected with the second end of the second resistor, the input end of the first microcontroller is connected with the first end of the second resistor, the first microcontroller is used for outputting first threshold voltage at a first sampling moment, the first microcontroller is further used for obtaining a second sampling moment when the first threshold voltage is reduced to the second threshold voltage, and the sensing parameters are obtained according to the first sampling moment and the second sampling moment.
Optionally, the capacitance detection module includes: the third resistor, the comparator, the fourth resistor, the fifth resistor and the second microcontroller; the first end of the third resistor is connected with the first input end of the comparator, the first end of the third resistor is also connected with the output end of the electrode, and the second end of the third resistor is connected with the output end of the comparator; the second input end of the comparator is connected with the first end of the fourth resistor, the second input end of the comparator is further connected with the first end of the fifth resistor, the output end of the comparator is connected with the second end of the fourth resistor, and the output end of the comparator is further connected with the second microcontroller.
Optionally, the bioelectrical detection module comprises: the input end of the electrostatic protection unit is connected with the output ends of the at least two detection electrodes and is used for performing electrostatic protection on the at least two detection electrodes; the input end of the low-noise amplification unit is connected with the output end of the electrostatic protection unit and is used for performing low-noise amplification on the original bioelectricity signals acquired by the at least two detection electrodes to obtain a preprocessed signal; and the input end of the filtering unit is connected with the output end of the low-noise amplification unit, and the output end of the filtering unit is connected with the comprehensive processing module and used for filtering the preprocessed signal to obtain the bioelectricity signal.
Optionally, the bioelectric detection module further comprises: the lead falling detection unit has its input connected to the output of the at least two detection electrodes and its output connected to the comprehensive processing module for conducting lead signal detection on the at least two detection electrodes.
Optionally, the at least two detection electrodes comprise: a first detection electrode, a second detection electrode, a third detection electrode, and a fourth detection electrode; the first detection electrode, the second detection electrode, the third detection electrode and the fourth detection electrode are uniformly arranged on the steering wheel, the first detection electrode, the second detection electrode, the third detection electrode and the fourth detection electrode are all connected with the load detection module, and the first detection electrode and the third detection electrode are also connected with the bioelectricity detection module.
In a second aspect, the present application provides a steering wheel comprising a driver hands-off and health detection device as described above.
In a third aspect, the present application provides a protective cover for a steering wheel, the protective cover comprising the above-mentioned driver hands-off and health detection device.
Compared with the prior art, the utility model has the following beneficial effects:
the method comprises the steps that at least two detection electrodes are arranged on the rim of a steering wheel, the hands-off detection result is obtained by detecting the induction parameters of the at least two detection electrodes, and the monitoring state of a detection target is obtained by detecting the bioelectricity signals connected with the at least two detection electrodes; therefore, the same electrodes are multiplexed, so that hands-off detection and health monitoring of the driver can be completed while the electrodes are not interfered with each other. Meanwhile, the method can judge whether the steering wheel is held by a human body, and avoids cheating the HOD detection system.
Drawings
FIG. 1 is a schematic flow chart illustrating a method for detecting a hands-off condition and a health condition of a driver according to an embodiment of the present disclosure;
FIG. 2 is a schematic diagram of an electrode arrangement provided in an embodiment of the present application;
fig. 3 is a schematic flow chart illustrating a hands-off detection result according to an embodiment of the present disclosure;
fig. 4 is a schematic flowchart illustrating a specific process of step S101 in fig. 1 according to an embodiment of the present disclosure;
FIG. 5 is a schematic structural diagram of a device for detecting hands-off and health of a driver according to an embodiment of the present disclosure;
FIG. 6 is a schematic structural diagram of a bioelectrical detection module according to an embodiment of the present disclosure;
fig. 7 is a schematic circuit diagram of an electrical capacitance detection module according to an embodiment of the present disclosure;
fig. 8 is a schematic circuit diagram of another capacitance detection module according to an embodiment of the present disclosure;
fig. 9 is a schematic circuit diagram illustrating IQ demodulation of a voltage signal according to an embodiment of the present disclosure.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In a first aspect, the present application provides a method for detecting a driver's hands-off and health, which specifically includes the following embodiments:
exemplary embodiment 1
Fig. 1 is a schematic flow chart of a method for detecting hands-off and health of a driver according to an embodiment of the present application, and as shown in fig. 1, the method for detecting hands-off and health of a driver specifically includes the following steps:
step S101, obtaining induction parameters of a detection electrode, wherein the detection electrode is arranged on a steering wheel.
It should be noted that, the number of the detection electrodes in this embodiment may be at least two, and the at least two detection electrodes may include two detection electrodes, which are respectively disposed on the left and right sides of the rim of the steering wheel main body, as shown in fig. 2, the black areas in fig. 2 are the first detection electrode and the second detection electrode, and the white gap between the black areas is the impedance isolation area; the at least two detection electrodes may further include four detection electrodes, six detection electrodes, and the like, and may be disposed on the rim of the steering wheel according to an actual application scenario.
The detection electrode has certain conductivity, the specific impedance meets the requirements of bioelectricity measurement and/or capacitance measurement, one reference conductivity requirement is surface resistance of about 2K ohm, each electrode is mutually insulated (or has high enough isolation impedance), and a simple realization method is to spray insulating materials on the adjacent parts of the two electrodes; for obtaining a good appearance effect, the electrode material may use leather or conductive fabric with a conductive surface, such as artificial leather or genuine leather coated with conductive PU.
In this embodiment, the sensing parameters include sensing signals and non-sensing signals, and the sensing signals include capacitance variation signals and impedance variation signals. It should be noted that when a human body approaches the sensing electrode, an additional capacitance is introduced, and by detecting a change in capacitance, it can be determined whether a human body or a hand approaches or touches the steering wheel, so that when a human body touches the electrode, an equivalent capacitance parameter corresponding to the electrode becomes large, and when no human body touches the electrode, an equivalent capacitance parameter corresponding to the electrode does not change, so that the sensing parameter corresponds to a capacitance change signal.
In this embodiment, in order to improve the detection accuracy, the impedance change of the human body contact can be directly measured, at this time, an ac signal needs to be applied to the sensing electrode, and is applied to the electrode in the form of a current source, and the voltage signal change to ground of the pickup electrode is detected at the same time, and the in-phase I and quadrature-phase Q signals are output after IQ demodulation, which are respectively equivalent to the equivalent resistor R and capacitor C to calculate the change of the load impedance.
Step S102, acquiring a bioelectrical signal of a detection target through at least two detection electrodes.
In this embodiment, the detection target is a driver, and when two hands of the driver hold two detection electrodes on a steering wheel, a limb lead is formed, so that a bioelectrical signal of the current driver can be detected, wherein the bioelectrical signal includes, but is not limited to, electrocardio, myoelectricity, and electrodermal signals; and amplifying, denoising and filtering the original bioelectric signals acquired by the at least two detection electrodes, and outputting the bioelectric signals of the detection target.
And S103, detecting the health state and/or the hand-off detection result of the detection target according to the induction parameters and the bioelectrical signals.
In this embodiment, when the sensing parameter includes a sensing signal and no sensing signal, outputting the hands-off detection result according to the sensing parameter and the bioelectric signal, including: when the bioelectric signals, the biological lead signals or the sensing signals of the two detection electrodes are detected, the hands-off detection result is a two-hand driving state; when an electrode is detected to have an induction signal, the hand-off detection result is in a one-hand driving state; and when the induction signal is not detected, the hands-off detection result is the hands-off driving state.
As shown in fig. 3, the specific results of the hands-off detection are: when the bioelectricity signal is detected, the hands are not in the holding state; when the biological lead signal is detected to exist currently, the hands-off detection result is a two-hand touch state; when two or more paths of capacitance induction signals are detected, the hands-off detection result is a two-hand touch state; when only one path of capacitance sensing signal is detected, the hand-off detection result is single-hand touch; and when no capacitance induction signal is detected, the hands-off detection result is the hands-off state.
Further, the present embodiment may further extract signals such as the heart rate, heart rate variability, and respiration of the detection target according to the bio-electrical signal, so as to output the current health state of the detection target, and further perform the fatigue state judgment.
Further, the present embodiment may further determine that the current state of holding the steering wheel is the most safe state according to the bio-electric signal, determine that the current state is the most unsafe state according to the hands-off state output by the hands-off detection result, and output a corresponding voice to perform an early warning prompt.
Further, the embodiment can also judge whether a human body (organism) holds the steering wheel according to whether the bioelectric signal meets a preset requirement (such as matching with an electrocardiogram template or calculating that the heart rate range is within a reasonable range), so that the accuracy of handshake detection is improved.
Compared with the prior art, the method has the following beneficial effects:
the method comprises the steps that at least two detection electrodes are arranged on the rim of a steering wheel, the hands-off detection result is obtained by detecting the induction parameters of the at least two detection electrodes, and the monitoring state of a detection target is obtained by detecting the bioelectricity signals connected with the at least two detection electrodes; therefore, the same electrodes are multiplexed, so that hands-off detection and health monitoring of the driver can be completed while the electrodes are not interfered with each other. Meanwhile, the method can judge whether the steering wheel is held by a human body, and avoids cheating the HOD detection system.
Exemplary embodiment two
Fig. 4 is a schematic flowchart illustrating a specific process of step S101 in fig. 1 according to an embodiment of the present disclosure; when the sensing parameter is a capacitance and/or resistance change parameter between a human body and a steering wheel, as shown in fig. 4, the step S101 of acquiring the sensing parameter of the detection electrode specifically includes the following steps:
step S201, generating an alternating current signal;
a step S202 of applying the alternating current signal to the detection electrode;
step S203, acquiring voltage change on the detection electrode;
in step S204, a value corresponding to the capacitance and/or resistance is obtained.
It should be noted that, after the sensing electrode is touched or approached by a hand, an additional equivalent capacitance and/or equivalent resistance is introduced to connect the equivalent capacitance and/or equivalent resistance of the human body in parallel with the equivalent capacitance and/or equivalent resistance of the electrode, so that the equivalent capacitance and/or equivalent resistance parameter after the sensing electrode is touched by the human body is greater than the equivalent capacitance and/or equivalent resistance parameter of the sensing electrode not touched by the human body, and therefore, as long as the change of the current equivalent capacitance and/or equivalent resistance parameter is measured, it can be detected whether the human body is currently in contact with the sensing electrode.
In this embodiment, obtaining the capacitance and/or resistance variation parameters includes: generating an alternating current signal; applying the alternating current signal to the detection electrode; acquiring voltage change on the detection electrode; a value comparable to the capacitance and/or resistance is obtained. The method comprises the following specific steps: outputting a first threshold voltage to an electrode at a first sampling moment, so that the first threshold voltage is the electrode is charged, the first threshold voltage is reduced, when the first threshold voltage is reduced to a second threshold voltage, recording the second sampling moment, subtracting the first sampling moment from the second sampling moment to obtain a discharge duration, comparing the discharge duration with a preset duration, when the discharge duration is greater than or equal to the preset duration, the induction parameter is that a human body contacts the electrode, and when the discharge duration is less than the preset duration, the induction parameter indicates that no human body contacts the electrode.
Exemplary embodiment three
In the embodiment, a contact change signal output by a load detection module is acquired; taking the contact change signal as a noise reference source to reduce the noise of the original bioelectricity signal, and reducing the noise of the original bioelectricity signal acquired by the at least two detection electrodes to obtain a preprocessed signal; and filtering the preprocessed signal to obtain the target bioelectricity signal.
It should be further noted that, because the automobile environment is easily interfered by the operation of the engine, etc., and the electrodes arranged on the steering wheel are essentially dry electrodes, the noise is relatively high compared with the wet electrodes, in order to improve the signal-to-noise ratio, a narrow effective bandwidth of the filter is set, which only includes the frequency region where the strength of the electrocardiograph signal is high, and the noise in other frequency regions is to be suppressed, in an embodiment of the present application, the high-frequency cutoff frequency is set to be lower than 30Hz, and the band-pass range of the filter is 0.5Hz to 29Hz (3dB bandwidth).
When the bioelectric signal is acquired, the contact noise also has a large influence on the measurement result, and in order to further eliminate the influence of the contact noise, the intensity change of the contact signal acquired by the load detection module can be used as a noise reference source, and the acquired bioelectric signal is subjected to self-adaptive noise reduction during signal comprehensive processing.
In another embodiment of the present application, the obtaining of the capacitance variation parameter further comprises the steps of: the oscillator is connected with the at least one detection electrode to obtain the oscillation frequency of the oscillator; and obtaining the induction parameters according to the oscillation frequency.
In another embodiment of the present application, acquiring a bioelectrical signal of a detection target by at least two detection electrodes includes: acquiring a contact change signal output by a load detection module; taking the contact change signal as a noise reference source to reduce noise of the original bioelectricity signal to obtain a preprocessed signal; and filtering the preprocessed signal to obtain the bioelectrical signal.
In another embodiment of the present application, when the at least two detection electrodes include a first detection electrode and a second detection electrode, acquiring the sensing parameter of the at least two detection electrodes further includes: acquiring a first detection parameter of the first detection electrode at a first detection moment; at a second detection moment, acquiring a second detection parameter of the second detection electrode; and obtaining the induction parameter according to the first detection parameter and the second detection parameter.
In another embodiment of the present application, when the number of the detection electrodes includes two or more, acquiring a bioelectrical signal of a detection target by the at least two detection electrodes includes: at the current moment, two target detection electrodes are selected from the multiple detection electrodes according to a preset rule; and acquiring a bioelectrical signal of a detection target through the two target detection electrodes.
In this embodiment, the detection electrodes disposed on the left and right sides of the steering wheel are generally selected to be used as the target detection electrodes, or customized selection may be performed according to the actual usage habits of the user, for example, a combination of an upper electrode and a lower electrode, an upper electrode and a right electrode, an upper electrode and a left electrode, and the like is selected to be used as the two target detection electrodes.
It should be noted that, in order to reduce the detection cost, in this embodiment, a switch is disposed between the load detection module and the plurality of detection electrodes, so as to multiplex the same load detection module to detect the sensing parameters of the plurality of electrodes.
It should be further noted that any two electrode combinations can be designed to form a pathway for measuring bioelectrical signals. For example, with a four-electrode arrangement, a switching unit is added between the four electrodes and the bioelectrical detection unit, such as a dual four-out-of-one analog switch using the integrated circuit chip CD 4052. The advantage of this is that holding arbitrary two electrodes and all being detectable bioelectricity signal with both hands, four electrodes all multiplex to have the function of bioelectricity detection and response parameter detection simultaneously this moment.
In a second aspect, the present application provides a device for detecting the hands-off and health of a driver, which specifically includes the following embodiments:
exemplary embodiment four
Fig. 5 is a schematic flow chart of a device for detecting hands-off and health of a driver according to an embodiment of the present application, and as shown in fig. 5, the device for detecting hands-off and health of a driver specifically includes:
the device comprises a detection electrode, a load detection module, a bioelectricity detection module and a comprehensive processing module;
the detection electrode is arranged on the steering wheel; the load detection module is connected with the at least one detection electrode and is used for acquiring the induction parameters of the at least one detection electrode; the bioelectricity detection module is connected with the at least two detection electrodes and is used for acquiring bioelectricity signals of a detection target through the at least two detection electrodes; the comprehensive processing module is connected with the load detection module and the bioelectricity detection module and is used for detecting the health state and/or the hands-off detection result of the detection target according to the sensing parameters and the bioelectricity signals.
It should be noted that, in the application, a plurality of electrodes are distributed on the steering wheel and are relatively independent, the bioelectricity detection module and the load detection module are simultaneously arranged, data of the bioelectricity detection module and the load detection module are comprehensively analyzed, and finally, the hands-off detection result and/or the health state are output. In this embodiment, the load detection module includes a capacitance detection module or an impedance detection module, where the capacitance detection module may be equivalent to detection of a capacitive reactance, and the impedance detection module may be equivalent to detection of a resistance and a capacitive reactance.
As shown in fig. 5, the at least two detection electrodes in this embodiment include: a first detection electrode, a second detection electrode, a third detection electrode, and a fourth detection electrode; the first detection electrode, the second detection electrode, the third detection electrode and the fourth detection electrode are uniformly arranged on the rim of the steering wheel main body, the first detection electrode, the second detection electrode, the third detection electrode and the fourth detection electrode are all connected with the load detection module, and the first detection electrode and the third detection electrode are also connected with the bioelectricity detection module.
In this embodiment, the detection apparatus further includes: the control end of the capacitance switching module is connected with the switching end of the load detection module, the first end of the capacitance switching module is connected with the input end of the load detection module, and the second end of the capacitance switching module switches between the output ends of the at least two detection electrodes and is used for connecting the matched electrode with the load detection module according to a switching signal output by the load detection module;
further, the capacitance switching module further includes: and the capacitance switching module enables the second end of the capacitance switching module to be connected with the turn-off position according to the turn-off signal output by the load detection module and is used for disconnecting the at least two detection electrodes from the load detection module.
It should be noted that, as shown in fig. 5, in this embodiment, a capacitance switching module is disposed between the capacitance detection module and the electrode, so as to multiplex the same impedance capacitance detection module to detect capacitance changes of multiple electrodes. In the capacitance switching module, an off position (off) may be optionally included, and when the impedance detection module outputs an excitation signal to the electrode (for example, an impedance test is performed by an ac signal), in order to avoid interference with the measurement of the bioelectrical signal, the switch of the capacitance detection module may be turned off at the moment of performing the bioelectrical signal acquisition.
In this embodiment, the detection apparatus further includes: the first end of the bioelectricity switching module is connected with the input end of the bioelectricity detection module, and the second end of the bioelectricity switching module and the third end of the bioelectricity switching module are switched between the output ends of the at least two detection electrodes and used for selecting two target electrodes to be connected with the bioelectricity detection module.
It should be noted that any two electrode combinations can be designed to form a pathway for measuring bioelectrical signals. For example, with a four-electrode arrangement, a switching unit needs to be added between the four electrodes and the bioelectrical detection module, for example, a dual-quad one-out-of-one analog switch using an integrated circuit chip CD4052 is used to perform the switching. This has the advantage that any two electrodes held by both hands can detect the bioelectrical signal. At the moment, the four electrodes are multiplexed to have the functions of bioelectricity detection and capacitance change detection at the same time. Of course, other electrode schemes may be devised, such as a total of two left and right electrodes or six electrodes, etc.
Exemplary embodiment five
FIG. 6 is a schematic structural diagram of a bioelectrical detection module according to an embodiment of the present disclosure; as shown in fig. 6, the bioelectric detection module includes:
the input end of the electrostatic protection unit is connected with the output ends of the at least two detection electrodes and is used for performing electrostatic protection on the at least two detection electrodes;
the input end of the low-noise amplification unit is connected with the output end of the electrostatic protection unit and is used for performing low-noise amplification on the original bioelectricity signals acquired by the at least two detection electrodes to obtain a preprocessed signal;
the input end of the filtering unit is connected with the output end of the low-noise amplifying unit, and the output end of the filtering unit is connected with the comprehensive processing module and used for filtering the preprocessed signal to obtain the bioelectricity signal;
the lead falling detection unit has its input connected to the output of the at least two detection electrodes and its output connected to the comprehensive processing module for conducting lead signal detection on the at least two detection electrodes.
It should be noted that, in this embodiment, the bioelectric signal may be electrocardiographic, myoelectric, and electrodermal, and taking the most common Electrocardiographic (ECG) measurement as an example, the first detection electrode and the second detection electrode correspond to two hands held on a steering wheel to form a limb lead, the frontmost end of the detection electrode includes an electrostatic protection unit, and then the detection electrode includes a low-noise amplification unit, a filtering unit, and a comprehensive processing unit to perform processing such as low-noise reduction, amplification filtering, and digital filtering, and finally output an electrocardiographic signal. The comprehensive processing unit can further extract or calculate signals such as heart rate, heart rate variability, respiration and the like from the electrocardiogram signals, and further can judge the fatigue state. The embodiment also comprises a lead falling detection unit for judging whether the hands are in good contact with the first detection electrode and the second detection electrode or not and outputting whether a lead signal exists or not; because the automobile environment is easily interfered by the running of an engine and the like, the electrodes arranged on the steering wheel are dry electrodes essentially, the noise is relatively high in humidity, the effective bandwidth of the filter is set to be narrow in order to improve the signal-to-noise ratio, the effective bandwidth only comprises a frequency region with high electrocardiosignal intensity, the noise of other frequency regions is restrained, the high-frequency cut-off frequency is set to be lower than 30Hz, and the band-pass range of the filter is 0.5 Hz-29 Hz (3dB bandwidth).
Exemplary embodiment six
In this embodiment, the capacitance detection module is used for detecting whether a hand touches the steering wheel, when a human body approaches the capacitance sensing electrode, an additional capacitance is introduced, and whether the human body or the hand touches the steering wheel can be judged by detecting the change of the capacitance; the capacitance detection and the bioelectricity detection are matched to use at least two electrode areas, the capacitance change of each electrode area can be independently detected, when the capacitance change is detected in any area, the steering wheel can be judged to be held by hands, and when the capacitance change is detected in both areas, the steering wheel can be judged to be held by both hands. In order to distinguish more detailed hand-holding actions, more independent detection areas can be divided on the steering wheel to determine which area is held by the hand. The capacitance switching module is arranged at the front end of the capacitance detection module, the capacitance change detection of a plurality of areas is realized through high-speed switching, and certainly, the capacitance change of different electrodes can be respectively detected by using a plurality of capacitance detection modules at the same time, but the cost and the volume of the circuit unit are increased.
Fig. 7 is a schematic circuit diagram of an electrical capacitance detection module according to an embodiment of the present disclosure; as shown in fig. 7, the capacitance detection module includes:
a first resistor R1, wherein a first end of the first resistor R1 is connected with an output end of the electrode;
a second resistor R2, wherein a first end of the second resistor R2 is connected with a second end of the first resistor R1;
the output end of the first microcontroller is connected with the second end of the second resistor R2, the input end of the first microcontroller is connected with the first end of the second resistor R2 and used for outputting a first threshold voltage at a first sampling moment, the first microcontroller is also used for obtaining a second sampling moment when the first threshold voltage is reduced to a second threshold voltage, and the induction parameters are obtained according to the first sampling moment and the second sampling moment.
It should be noted that the sensing electrode is connected to the first microcontroller through a first resistor R1 and a second resistor R2, and the sensing electrode has an equivalent fixed capacitance C with respect to groundXThe human body has an equivalent variable capacitance C to the groundT(ii) a At time t1, when the output OUT of the first microcontroller is high and the input IN of the first microcontroller is configured IN input mode (high trigger), an additional capacitance C is introduced when the sensing electrode is touched or approached by handT. The first threshold voltage output from the output terminal OUT of the first microcontroller is transmitted to the capacitor C through the second resistor R2 and the first resistor R1X(and C)T) Charging, triggering interruption of the IN port when the second threshold voltage is reached (time T2), duration T and C between time T2 and time T1XAnd CTThe equivalent capacitance in parallel connection is related, and whether a hand approaches or touches the induction electrode can be judged through the time length change of T.
Exemplary embodiment seven
Fig. 8 is a schematic circuit diagram of another capacitance detection module provided in the embodiment of the present application, and as shown in fig. 8, the capacitance detection module may further include:
a third resistor R3, a comparator CM, a fourth resistor R4, a fifth resistor R5 and a second microcontroller;
a first end of the third resistor R3 is connected to a first input terminal of the comparator CM, a first end of the third resistor R3 is further connected to an output terminal of the electrode, and a second end of the third resistor R3 is connected to an output terminal of the comparator CM;
the second input end of the comparator CM is connected with the first end of the fourth resistor R4, the second input end of the comparator CM is further connected with the first end of the fifth resistor R5, the output end of the comparator CM is connected with the second end of the fourth resistor R4, and the output end of the comparator CM is further connected with the second microcontroller.
In this embodiment, an RC oscillator is configured by the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the comparator CM, a human body sensing capacitance is introduced into the oscillation circuit, and thus a change in the human body sensing capacitance changes the frequency of the RC oscillator, and whether contact/proximity is determined by detecting the change in the frequency. In the RC relaxation oscillator shown in FIG. 8, when the frequency of the output waveform Vo follows CTThe calculation formula of the oscillation frequency f is changed as follows:
wherein C is CXAnd CTAnd equivalent capacitance connected in parallel.
Therefore, as long as the change in the oscillation frequency is detected, the change in the induced capacitance can be determined. Since the output of the relaxation oscillator is square wave, all oscillation frequencies can be conveniently obtained by counting through a second microcontroller or a special counter.
In this embodiment, the contact capacitance is introduced when the human body is in contact with the load, and the equivalent resistance is also introduced when the human body is in contact with the load, so that in order to improve the detection accuracy, the impedance change can be directly measured, and at this time, an alternating current signal needs to be applied to the sensing electrode, and the change of the load impedance is calculated by detecting the response change under the action of the alternating current signal. Fig. 9 is a circuit diagram of impedance detection. A sinusoidal signal is generated through an internal oscillation circuit or a digital-to-analog conversion circuit and loaded on the electrode in the form of a current source, meanwhile, a voltage signal to ground of the pickup electrode is detected, and an in-phase I signal and a quadrature-phase Q signal are output after IQ demodulation and are respectively equivalent to an equivalent resistor R and a capacitor C.
In a third aspect, embodiments of the present application provide a steering wheel including the above-described driver hands-off and health detection apparatus.
In a fourth aspect, the present application provides a protective sheath for a steering wheel, where the protective sheath includes the above-mentioned driver hands-off and health detection device.
Finally, the health detection function and the hands-off detection function are simultaneously arranged on the steering wheel, at least two detection electrodes are distributed on the steering wheel, the bioelectricity signals and the capacitance change signals connected by the two electrodes are detected, and the bioelectricity and capacitance detection is completed by multiplexing the two electrodes, so that the health information and the hands-off detection information can be acquired without mutual interference; the method comprises the steps of detecting the hands-off with biological contact function judgment, acquiring capacitance change and bioelectric signals through at least two detection electrodes arranged on a steering wheel, and outputting signals for hands-off and organism holding; through multi-electrode switching, the bioelectricity signals and the hand-off information can be detected when the steering wheel is held by any two electrodes on the steering wheel.
It is noted that, in this document, relational terms such as "first" and "second," and the like, may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
Claims (10)
1. A driver hands-off and health detection device, the detection device comprising:
the device comprises a detection electrode, a load detection module, a bioelectricity detection module and a comprehensive processing module;
the load detection module is connected with the detection electrodes and is used for acquiring the induction parameters of at least one detection electrode;
the bioelectricity detection module is connected with at least two detection electrodes and is used for acquiring bioelectricity signals of a detection target through the at least two detection electrodes;
the comprehensive processing module is connected with the load detection module and the bioelectricity detection module and is used for detecting the health state and/or the hands-off detection result of the detection target according to the sensing parameters and the bioelectricity signals.
2. The driver hands-off and health detection device as in claim 1, wherein the detection device further comprises:
the first end of the bioelectricity switching module is connected with the input end of the bioelectricity detection module, and the second end of the bioelectricity switching module and the third end of the bioelectricity switching module are switched between the output ends of the at least two detection electrodes and used for selecting two target electrodes to be connected with the bioelectricity detection module.
3. The driver hands-off and health detection device as in claim 1, wherein the load detection module comprises: a capacitance detection module or an impedance detection module.
4. The driver hands-off and health detection device of claim 3, wherein the capacitive detection module comprises:
the first end of the first resistor is connected with the output end of the electrode;
a first end of the second resistor is connected with a second end of the first resistor;
the output end of the first microcontroller is connected with the second end of the second resistor, the input end of the first microcontroller is connected with the first end of the second resistor, the first microcontroller is used for outputting first threshold voltage at a first sampling moment, the first microcontroller is further used for obtaining a second sampling moment when the first threshold voltage is reduced to the second threshold voltage, and the sensing parameters are obtained according to the first sampling moment and the second sampling moment.
5. The driver hands-off and health detection device of claim 3, wherein the capacitive detection module comprises:
the third resistor, the comparator, the fourth resistor, the fifth resistor and the second microcontroller;
the first end of the third resistor is connected with the first input end of the comparator, the first end of the third resistor is also connected with the output end of the electrode, and the second end of the third resistor is connected with the output end of the comparator;
the second input end of the comparator is connected with the first end of the fourth resistor, the second input end of the comparator is further connected with the first end of the fifth resistor, the output end of the comparator is connected with the second end of the fourth resistor, and the output end of the comparator is further connected with the second microcontroller.
6. The operator hands-off and health detection device as in claim 1, wherein the bioelectrical detection module comprises:
the input end of the electrostatic protection unit is connected with the output ends of the at least two detection electrodes and is used for performing electrostatic protection on the at least two detection electrodes;
the input end of the low-noise amplification unit is connected with the output end of the electrostatic protection unit and is used for performing low-noise amplification on the original bioelectricity signals acquired by the at least two detection electrodes to obtain a preprocessed signal;
and the input end of the filtering unit is connected with the output end of the low-noise amplification unit, and the output end of the filtering unit is connected with the comprehensive processing module and used for filtering the preprocessed signal to obtain the bioelectricity signal.
7. The driver hands-off and health detection device of claim 6, wherein the bioelectrical detection module further comprises:
the lead falling detection unit has its input connected to the output of the at least two detection electrodes and its output connected to the comprehensive processing module for conducting lead signal detection on the at least two detection electrodes.
8. The driver hands-off and health detection apparatus as claimed in any one of claims 1 to 7, wherein the at least two detection electrodes comprise:
a first detection electrode, a second detection electrode, a third detection electrode, and a fourth detection electrode;
the first detection electrode, the second detection electrode, the third detection electrode and the fourth detection electrode are uniformly arranged on a steering wheel, the first detection electrode, the second detection electrode, the third detection electrode and the fourth detection electrode are all connected with the load detection module, and the first detection electrode and the third detection electrode are also connected with the bioelectricity detection module.
9. A steering wheel, characterized in that it comprises a driver hands-off and health detection device according to any one of claims 1-8.
10. A protective cover for a steering wheel, said protective cover comprising a hands-free and health-detection device as claimed in any one of claims 1 to 8.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202121014207.6U CN215503051U (en) | 2021-05-12 | 2021-05-12 | Driver hands-off and health detection device, steering wheel and protective sleeve |
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| CN202121014207.6U CN215503051U (en) | 2021-05-12 | 2021-05-12 | Driver hands-off and health detection device, steering wheel and protective sleeve |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115123261A (en) * | 2022-09-01 | 2022-09-30 | 国网浙江省电力有限公司宁波市北仑区供电公司 | Driving early warning method, device and system |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115123261A (en) * | 2022-09-01 | 2022-09-30 | 国网浙江省电力有限公司宁波市北仑区供电公司 | Driving early warning method, device and system |
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