Platform and method for testing response of millimeter wave radar heart rate monitoring error to external parameters

Abstract

The invention discloses a millimeter wave radar heart rate monitoring error external parameter response test platform comprising the following structures: a pedestal horizontally arranged; the two optical shafts are arranged on the base in a supporting manner; the screw rod is provided with an external thread and is arranged between the two optical shafts, and the screw rod is rotatably supported on the base; the first stepping motor is arranged on the base, and the output end of the first stepping motor is connected with one end of the lead screw; the driving horizontal sliding block is provided with two unthreaded holes and a threaded hole, the two unthreaded shafts are arranged in the unthreaded holes respectively, and external threads of the lead screw are matched with the threaded hole; the second stepping motor is fixedly arranged at the top of the driving horizontal sliding block; the steering engine is connected with the output end of the second stepping motor; and the millimeter wave radar wave mechanism is fixedly arranged on the steering engine. The limitation that a traditional contact type monitoring device cannot be applied in multiple scenes can be overcome, and the monitoring precision is improved.

Description

Technical Field

[0001] The present invention relates to an experimental platform and method for the response of millimeter-wave radar heart rate monitoring error to external parameters, belonging to the field of automotive technology. Background Technique

[0002] In previous related studies, the entire driving process was divided into three stages: perception, judgment, and response. Regardless of which stage, the driver's operations are closely related to their physiological and psychological states. Abnormal physiological and psychological states will directly affect the driver's perception, judgment, and corresponding operations. Among them, fatigue driving, emotional driving, distracted driving, and sudden illnesses will greatly affect the driver's perception, judgment, and operation response. Heart rate and heart rate variability are important parameters characterizing the health status of the autonomic nervous system. Clinically, the health status of the autonomic nervous system is monitored by extracting the heart rate and using algorithms to calculate the heart rate variability, and migrating it into the cockpit can effectively monitor the sudden illnesses of the driver. In addition, the fatigue level and emotion of the driver are also closely related to their heart rate, and the heart rate signal can effectively characterize the emotional state and distraction level of the driver and passengers. Therefore, monitoring the driver's heart rate can be used as the basis for driver state recognition.

[0003] The detection methods for the emotional state and distraction level of the driver and passengers can be classified according to physiological and non-physiological methods. Among them, the physiological method mainly detects by monitoring the physiological signals of the human body. This type of method involves sensor and data processing technologies and can provide objective detection results. Common methods include: electroencephalogram (EEG), electrocardiogram (ECG), galvanic skin response (GSR), eye movement tracking, facial expression analysis, and methods based on respiratory rate and blood oxygen saturation. The non-physiological method mainly relies on environmental and behavioral monitoring data. This type of method usually uses computer vision, machine learning, and other data analysis tools to evaluate the driver's state. Common methods include: camera monitoring, driving behavior analysis, sound detection, and interaction data between the driver and the vehicle-mounted system.

[0004] Although non - physiological methods have many advantages in emotion and distraction detection, such as being easy to implement and relatively not requiring complex sensors, they also have great drawbacks: there are external factor interferences, limited information sources, and limited accuracy caused by algorithm errors; in addition, there are also issues related to user privacy and data security risks; moreover, due to over - reliance on technology and equipment, if the training data is not sufficient to cover various emotions and distraction situations, the detection effect will be discounted. In actual applications, user behaviors are diverse, and there are significant differences in the facial expressions, body movements, and speech characteristics of different individuals. Some people may not show obvious states such as anxiety or distraction, and some people have specific habits, such as frequently scratching their heads or moving their eyes, which may be misinterpreted as distraction or emotional fluctuations, increasing the detection difficulty. Also, in bumpy road conditions, congested traffic, or when driving at high speeds, cameras or microphones cannot accurately capture the characteristics of drivers. When drivers are performing multiple tasks simultaneously (such as adjusting navigation, listening to music, etc.), non - physiological methods are also difficult to accurately judge their attention concentration.

[0005] In summary, the emotional state and distraction level of passengers are usually detected by physiological methods, and physiological indicators are usually collected in a contact - based manner. This contact - based collection method has poor adaptability to some scenarios that require frequent movement or are not convenient for wearing electrodes (such as during driving), is mainly applied to clinical diagnosis, and is not convenient to use in the cockpit, which will bring a burden to passengers. Millimeter - wave radar technology has significant advantages in non - contact heart rate monitoring of passengers. It can achieve long - distance, real - time, and high - precision heart rate monitoring, does not require wearing equipment, and improves user comfort. At the same time, the radar has strong penetration, is not affected by ambient light, and can work stably in the dark or complex conditions. In addition, millimeter - wave radar protects privacy, does not capture clear images, and has the characteristics of low power consumption and miniaturization, which is convenient for integration into automobiles. These characteristics make it have great application prospects in improving driving safety and the driving experience.

[0006] When using millimeter - wave radar to monitor the heart rate of passengers, the monitoring accuracy is closely related to the installation position of the radar. The heart rate monitoring of passengers by the radar at different positions will be affected by various external factors, such as seat structure, other in - vehicle equipment, human body posture, and motion state. Therefore, in order to ensure the accuracy and reliability of heart rate monitoring, it is necessary to conduct systematic experimental studies to analyze and quantify the response of monitoring errors to these external parameters. Such experiments not only help to identify potential influencing factors but also provide data support for the optimal installation of millimeter - wave radar, enabling it to obtain more accurate and stable monitoring effects in actual applications. Finally, with the help of these experimental results, the installation of the radar in the cockpit can be optimized to achieve the efficiency and consistency of heart rate monitoring, thus better meeting the needs of intelligent cockpit health monitoring. Summary of the Invention

[0007] The present invention designs and develops an experimental platform for the response of millimeter-wave radar heart rate monitoring error to external parameters, which can adjust the monitoring position and improve the monitoring accuracy and reliability.

[0008] The technical solution provided by the present invention is as follows:

[0009] An experimental platform for the response of millimeter-wave radar heart rate monitoring error to external parameters, comprising:

[0010] A base, which is horizontally arranged;

[0011] Two optical axes, which are supported and arranged on the base;

[0012] A lead screw, which has an external thread and is arranged between the two optical axes. The lead screw is rotatably supported on the base; the axes of the two optical axes and the lead screw are located in the same plane;

[0013] A first stepping motor, which is arranged on the base, and the output end of the first stepping motor is connected to one end of the lead screw;

[0014] A driving horizontal slider, on which two light holes and a threaded hole are provided. The two optical axes are respectively arranged in the light holes, and the external thread of the lead screw is matched with the threaded hole;

[0015] A second stepping motor, which is fixedly arranged on the top of the driving horizontal slider;

[0016] A servo motor, which is connected to the output end of the second stepping motor;

[0017] A millimeter-wave radar wave mechanism, which is fixedly arranged on the servo motor.

[0018] Preferably, it further comprises:

[0019] A first side plate, which is fixedly arranged at one end of the base, and the stepping motor is fixedly arranged on the first side plate;

[0020] A second side plate, which is fixedly arranged at the other end of the base and is arranged opposite to the first side plate;

[0021] An intermediate plate, which is arranged on the base and is close to the first side plate.

[0022] Preferably, the intermediate plate is provided with light holes and threaded holes corresponding to the driving horizontal slider one by one.

[0023] Preferably, it further comprises:

[0024] A slide rail, one end of which is fixedly arranged on the second stepping motor;

[0025] A slider, which is matched and arranged on the slide rail. The servo is fixedly arranged on the slider and can move up and down along the slide rail with the slider.

[0026] A belt, which is connected to the output end of the second stepper motor, passes through and is fixed between the slider and the servo, so that the belt is attached to the slide rail. When the second stepper motor rotates, the slider and the servo are driven to move up and down through the belt.

[0027] Preferably, the millimeter-wave radar mechanism includes:

[0028] A millimeter-wave radar bracket, which is arranged at the output end of the servo;

[0029] A millimeter-wave radar, which is arranged on the millimeter-wave radar bracket.

[0030] Preferably,

[0031] Both ends of the two optical axes are respectively fixedly arranged on the first side plate and the second side plate, and the middle part sequentially passes through the middle plate and the driving horizontal slider;

[0032] One end of the lead screw is connected to the first stepper motor, the middle part is matched and arranged in the threaded holes of the middle plate and the driving horizontal slider, and the other end is rotatably supported on the second side plate.

[0033] Preferably, it further includes:

[0034] A first laser ranging module, which is fixedly arranged on the middle plate;

[0035] A second laser ranging module, which is fixedly arranged on the second stepper motor.

[0036] Preferably, it further includes:

[0037] A main control unit, whose output end is electrically connected to the servo and the first stepper motor;

[0038] An upper computer, which is bidirectionally electrically connected to the main control unit and can collect heart rate data;

[0039] A millimeter-wave radar, which is bidirectionally electrically connected to the main control unit;

[0040] The input end of the servo is electrically connected to the output end of the main control unit;

[0041] The input ends of the first stepper motor and the second stepper motor are respectively electrically connected to the main control unit.

[0042] An experimental method for the response of millimeter-wave radar heart rate monitoring error to external parameters, characterized in that the experimental platform for the response of millimeter-wave radar heart rate monitoring error to external parameters is used, including:

[0043] Build an experimental platform;

[0044] In the host computer, set the moving values of the first stepping motor and the second stepping motor, and perform real-time correction through the millimeter-wave radar;

[0045] The millimeter-wave radar emits millimeter-wave signals and receives reflected signals. The heart rate is transmitted into the host computer software through the main control module. The collected data is displayed in the data acquisition pane and plotted in the coordinates for visual display of the real-time heart rate.

[0046] Preferably, the calculation formulas for the distance d between the millimeter-wave radar and the subject and the pitch angle α of the millimeter-wave radar are:

[0047] X_pos = d × cosα - 40;

[0048] Y_pos = d × sinα;

[0049] In the formula, X_pos is the horizontal position of the millimeter-wave radar target, and Y_pos is the vertical position of the millimeter-wave radar target.

[0050] The beneficial effects of the present invention:

[0051] This experimental platform has the characteristics of high precision and high reliability, and can effectively overcome the limitations of traditional contact heart rate monitoring methods in some scenarios, such as the inconvenience that may be caused in a mobile environment and the restriction on the activities of the monitored person. It can be widely applied to the field of automotive driving safety to monitor the heart rate status of drivers in real time to prevent fatigue driving and other situations, and is also suitable for remote and non-intrusive monitoring of the heart rate of personnel in the fields of smart home and healthcare, providing an innovative, efficient and promising heart rate monitoring solution for related fields. Description of the Drawings

[0052] Figure 1 is an axonometric view of an experimental platform for the response of millimeter-wave radar heart rate monitoring error to external parameters according to the present invention

[0053] Figure 2 is a side view of an experimental platform for the response of millimeter-wave radar heart rate monitoring error to external parameters according to the present invention.

[0054] Figure 3 is a top view of an experimental platform for the response of millimeter-wave radar heart rate monitoring error to external parameters according to the present invention.

[0055] Figure 4It is a relative position diagram of the test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters described in the present invention during the test and the test subject.

[0056] Figure 5 It is a block diagram of the test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters described in the present invention.

[0057] Figure 6 It is the operation interface of the test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters described in the present invention. Detailed implementation manners

[0058] The following further describes the present invention in detail with reference to the accompanying drawings so that those skilled in the art can implement it according to the text of the specification.

[0059] As Figures 1-6 shown, the present invention provides a test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters, including: a first laser ranging module 1, a first stepping motor 2, a first side plate 3, an intermediate plate 4, a servo motor 5, a millimeter-wave radar bracket 6, a second stepping motor 7, a driving horizontal slider 8, a second side plate 9, a base 10, a lead screw 11, a second laser ranging module 12, an optical axis 13, a slider 14, a slide rail 15, and a belt 16.

[0060] The base 10 is horizontally arranged. On the base 10, two optical axes 13 are rotatably supported. The lead screw 11 is rotatably supported on the base 10 and is located between the two optical axes 11. At the same time, the axes of the two optical axes and the lead screw 11 are in the same plane.

[0061] The first side plate 3 is fixedly arranged at one end of the base 10, and the first stepping motor 2 is fixedly arranged on the first side plate 3; the second side plate 9 is fixedly arranged at the other end of the base 10 and is arranged opposite to the first side plate 3; the intermediate plate 4 is arranged on the base 10 and is close to the first side plate 3. The output end of the first stepping motor 2 is connected to the lead screw 11; two light holes and a threaded hole are provided on the driving horizontal slider 8, and corresponding light holes and threaded holes are provided on the intermediate plate 4. The middle parts of the two optical axes are respectively arranged in the light holes, and the external thread of the lead screw 11 is matched with the threaded hole; by driving the lead screw 11 to rotate by the first stepping motor 2, the position of the driving horizontal slider 8 is changed.

[0062] A second stepping motor 7 is fixedly arranged at the top of the driving horizontal slider 8. At the top of the second stepping motor 7, a slide rail 15 is vertically fixedly arranged. A slider 14 is arranged in a matching manner on the slide rail. A servo 5 is fixedly arranged on the slider 14 and can move relatively along the slide rail 15. The output end of the second stepping motor 7 is connected with a belt 16. The belt 16 passes through and is fixedly arranged between the slider 14 and the servo 5 and makes the belt 16 adhere to the slide rail 15. When the second stepping motor 7 rotates, the slider 14 and the servo 5 are driven to move up and down through the belt 16. The millimeter-wave radar wave bracket 6 is arranged on the servo 5. The first laser ranging module 1 is fixedly arranged on the middle plate 4; the second laser ranging module 13 is fixedly arranged on the second stepping motor 7.

[0063] The output end of the main control unit is electrically connected to the servo 5 and the first stepping motor 2; the upper computer is bidirectionally electrically connected to the main control unit and can collect heart rate data; the millimeter-wave radar is bidirectionally electrically connected to the main control unit; the input end of the servo 5 is electrically connected to the output end of the main control unit; the input ends of the first stepping motor 2 and the second stepping motor 7 are electrically connected to the main control unit.

[0064] The present invention also provides a test method for exploring the response of the millimeter-wave radar heart rate monitoring error to its external parameters, which is characterized in that the test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters is used, including:

[0065] Build a test platform;

[0066] In the upper computer, set the moving values of the first stepping motor and the second stepping motor and perform real-time correction through the millimeter-wave radar;

[0067] The millimeter-wave radar emits millimeter-wave signals and receives reflected signals. The heart rate is transmitted into the upper computer software through the main control module. The collected data is displayed in the data acquisition pane and plotted in the coordinates for visual display of the real-time heart rate.

[0068] The calculation formulas for the distance d between the millimeter-wave radar and the subject and the pitch angle α of the millimeter-wave radar are:

[0069] X_pos = d×cosα - 40;

[0070] Y_pos = d×sinα;

[0071] In the formula, X_pos is the horizontal position of the millimeter-wave radar target, and Y_pos is the vertical position of the millimeter-wave radar target.

[0072] During operation, a test platform composed of a millimeter-wave radar, a servo motor, an optical axis lead screw, and a base is built. The movement of the stepper motor and the servo motor is controlled in the upper computer, thereby controlling the position of the millimeter-wave radar. The position is corrected in real time through the serial port ranging module, so as to realize non-contact heart rate monitoring of the occupants in a vehicle or other specific environments. The millimeter-wave radar emits millimeter-wave signals and receives the reflected signals. The heart rate data is transmitted into the data acquisition upper computer software through Arduino. The collected data is displayed in the data acquisition pane and plotted in the coordinates on the right half for visual display of the real-time heart rate.

[0073] The adjustability of the test bench is realized by two stepper motors and a servo motor. The millimeter-wave radar is fixed on the bracket connected to the output shaft of the servo motor. The servo motor is rigidly connected to the slider on the vertical track and can move up and down with the slider. The second stepper motor in the vertical direction and the vertical track are fixed on the slider in the horizontal direction together. The first stepper motor in the horizontal direction pushes the slider to move back and forth through the lead screw for distance adjustment, and the servo motor adjusts the pitch angle of the millimeter-wave radar. In order to ensure that the normal line of the millimeter-wave radar plane can still point to the chest cavity of the subject after the pitch angle changes, the stepper motor in the vertical direction adjusts the height of the millimeter-wave radar.

[0074] In the prior art, it is not suitable to perform heart rate monitoring on the left and right sides of the measured target by the millimeter-wave radar. After testing, the present invention can obtain the parameter settings for real vehicle layout in the future, and can avoid the occlusion of the driver's line of sight by the radar and prevent interference from the steering wheel and other components to the path of the millimeter-wave radar. Therefore, the millimeter-wave radar in the due front is arranged on the upper edge of the front windshield, and the angle between the radar plane and the vertical line is 35° to ensure that when the driver is in a comfortable sitting position, the angle between the normal direction of the millimeter-wave radar and the normal direction of the chest cavity surface of the subject is close to 0°. In addition, the heart rate monitoring error changes little within an angle of 20° between the two, and normal heart rate monitoring can still be ensured after the backrest angle is adjusted. When the driver turns and sits sideways, the millimeter-wave radar in the due front cannot cover the surface of his chest cavity, resulting in signal distortion and inability to monitor his heart rate. In order to ensure that the heart rate data can still be monitored after the driver sits sideways, the remaining millimeter-wave radars are respectively arranged at the junction of the left A-pillar and the instrument panel and in the center of the instrument panel, and the horizontal angle between them and the lower edge of the front windshield is adjusted to 60° to ensure that it faces the driver sitting sideways.

[0075] Although the embodiments of the present invention have been disclosed as above, it is not limited to only the applications listed in the description and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the field, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the illustrated examples here.

Claims

1. An experimental platform for the response of millimeter-wave radar heart rate monitoring error to external parameters, characterized in that, Comprising: A base, which is horizontally arranged; Two optical axes, which are supported and arranged on the base; A lead screw, which has an external thread and is arranged between the two optical axes, and the lead screw is rotatably supported on the base; the axes of the two optical axes and the lead screw are located in the same plane; A first stepping motor, which is arranged on the base, and the output end of the first stepping motor is connected to one end of the lead screw; A driving horizontal slider, on which two optical holes and a threaded hole are provided, the two optical axes are respectively arranged in the optical holes, and the external thread of the lead screw is matched with the threaded hole; A second stepping motor, which is fixedly arranged on the top of the driving horizontal slider; A servo motor, which is connected to the output end of the second stepping motor; A millimeter wave radar wave mechanism, which is fixedly arranged on the servo motor.

2. The test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters according to claim 1, characterized in that, Further comprising: A first side plate, which is fixedly arranged at one end of the base, and the stepping motor is fixedly arranged on the first side plate; A second side plate, which is fixedly arranged at the other end of the base and is arranged opposite to the first side plate; An intermediate plate, which is arranged on the base and is close to the first side plate.

3. The test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters according to claim 2, characterized in that, The intermediate plate is provided with optical holes and threaded holes corresponding to the driving horizontal slider one by one.

4. The test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters according to claim 3, characterized in that Further comprising: A slide rail, one end of which is fixedly arranged on the second stepping motor; A slider, which is matched with the slide rail, and the servo motor is fixedly arranged on the slider and can move up and down along the slide rail with the slider; A belt, which is connected to the output end of the second stepping motor, passes through and is fixed between the slider and the servo motor, so that the belt is attached to the slide rail. When the second stepping motor rotates, the slider and the servo motor are driven to move up and down through the belt.

5. The test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters according to claim 4, characterized in that, The millimeter wave radar mechanism comprises: A millimeter wave radar bracket, which is arranged at the output end of the servo motor; A millimeter wave radar, which is arranged on the millimeter wave radar bracket.

6. The test platform for the response of the millimeter wave radar heart rate monitoring error to external parameters according to claim 5, characterized in that Both ends of the two optical axes are respectively fixedly arranged on the first side plate and the second side plate, and the middle parts sequentially pass through the intermediate plate and the driving horizontal slider; One end of the lead screw is connected to the first stepping motor, the middle part is matched and arranged in the threaded holes of the intermediate plate and the driving horizontal slider, and the other end is rotatably supported on the second side plate.

7. The test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters according to claim 6, characterized in that, Further comprising: A first laser ranging module, which is fixedly arranged on the intermediate plate; A second laser ranging module, which is fixedly arranged on the second stepping motor.

8. The test platform for the response of the millimeter-wave radar heart rate monitoring error to external parameters according to claim 7, characterized in that, Further comprising: A main control unit, whose output end is electrically connected to the servo motor and the first stepping motor; An upper computer, which is bidirectionally electrically connected to the main control unit and can collect heart rate data; A millimeter wave radar, which is bidirectionally electrically connected to the main control unit; The input end of the servo motor is electrically connected to the output end of the main control unit; The input ends of the first stepping motor and the second stepping motor are respectively electrically connected to the main control unit.

9. An experimental method for the response of millimeter-wave radar heart rate monitoring error to external parameters, characterized in that, Using the test platform for the response of the millimeter wave radar heart rate monitoring error to external parameters according to any one of claims 1-8, comprising: Building a test platform; In the host computer, set the movement values of the first stepping motor and the second stepping motor, and perform real-time correction through the millimeter-wave radar. The millimeter-wave radar emits millimeter-wave signals and receives reflected signals. The heart rate is transmitted into the host computer software through the main control module. The collected data is displayed in the data acquisition pane and plotted in the coordinates for visual display of the real-time heart rate.

10. The test method for the response of the millimeter-wave radar heart rate monitoring error to external parameters according to claim 9, characterized in that, The calculation formulas for the distance d between the millimeter-wave radar and the subject and the pitch angle α of the millimeter-wave radar are as follows: X_pos = d × cosα - 40; Y_pos = d × sinα; In the formula, X_pos is the horizontal position of the millimeter-wave radar target, and Y_pos is the vertical position of the millimeter-wave radar target.

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