CN102602363A - Method and device for vehicle passive keyless entering, starting and locking based on ultra-wide band - Google Patents

Abstract

The invention discloses a method and device for keyless entry, start and lock of a vehicle based on ultra-broadband. Sensors, start/stop buttons, seat sensors, and body antenna arrays are all connected to the main controller through the body circuit; the method uses UWB signals to precisely locate the vehicle key, and simultaneously detects the vehicle key for each trigger action of the driver The position and the position information of the people in the car are used to control the work of the door lock, start system and alarm system by means of joint judgment. In addition, the vehicle key can also record and store information that the driver is interested in and vehicle dynamic information. The present invention can better avoid accidents caused by misjudgment by the main controller or misoperation by personnel.

Description

Ultra-broadband-based vehicle keyless entry, starting and locking method and device

technical field

The invention relates to automobile safety and anti-theft electronic technology and wireless communication technology, in particular to a vehicle keyless entry and start method and device based on Ultra Wide-Band (UWB) positioning.

Background technique

With the popularity of automobiles, people have put forward higher requirements for automobile safety and convenience. High-reliability anti-theft, smart entry, keyless start, high integration, and real-time communication are the trends in the development of intelligent vehicles.

The original car anti-theft is only accomplished by a simple mechanical lock, which is very easy to be destroyed and has low security. In 1994, NXP Semiconductors (Philips Semiconductors at the time) successfully applied Radio Frequency Identification (RFID) technology to automotive electronic engine locks for the first time. Communication realizes key identification, and judges whether to unlock the door lock and electronic engine lock. Even if the thief opens the car door and connects the starter circuit, the engine cannot be started because of no authentication. This electronic engine anti-theft method greatly improves the anti-theft performance of the car, making it popular in Europe and North America soon, and greatly reducing the car theft rate in Europe in just a few years, so it soon became the Standard equipment for European cars.

Although the remote control key has improved the anti-theft performance of the car, its secrecy is poor, and it is easy to be interfered, cracked and copied by humans, which restricts its development. Subsequently, the emergence of the Passive Keyless Enter (PKE) system has repaired the shortcoming of the poor security of the remote control key. As the core technology of the new generation of automotive safety and anti-theft intelligent electronic systems, the keyless entry system has completely changed the development prospects of the automotive safety and anti-theft application field, bringing users a new experience of comfort and convenience. The driver does not need to use the key during the whole process from entering to leaving the vehicle, and only needs to carry the key with him. High-precision wireless positioning technology is the prerequisite for keyless entry, so positioning accuracy has also become the most important technical index of the car keyless entry system.

The current keyless entry system can basically complete key sensing, key legality detection, and automatically unlock the car door without operating the key. Currently, the mainstream technology used in the keyless entry system to realize vehicle key location is based on receiving low-frequency (125KHz) signal strength detection to realize location. According to the Received Signal Strength Indicator (RSSI), that is, according to the attenuation degree of the received low-frequency signal, the relative distance between the key and the low-frequency antenna in the car is calculated, and the spatial position of the key relative to the vehicle body is located by crossing the coverage of multiple low-frequency antennas. However, through market research and analysis, it is found that the above RSSI-based keyless entry system has the following disadvantages:

(1) The positioning accuracy is not high. This method relies on the path loss model of signal propagation, which is greatly affected by changes in the communication environment in practical applications. When the two cars are too close to each other or the vehicle key is close to the door, etc., because the car itself is a strong scatterer of electromagnetic waves, the path loss model will be distorted, causing misjudgment in the keyless entry system. For example, the Mercedes-Benz E280 car experienced a malfunction in which the door lock function failed when the driver left the vehicle, and the instrument displayed "the key is in the car". The Chevrolet CRUZE sedan also has the failure phenomenon that the door cannot be opened when it is too close to other vehicles. According to statistical analysis, the positioning accuracy of the RSSI-based keyless entry system of existing mainstream models is 5-10cm, which is the main cause of the above failure.

(2) The extremely narrow-frequency low-frequency signal is susceptible to human interference and cracking, so that the anti-theft performance of the keyless entry system has no essential improvement compared with the remote control key. Now there are various "car jammers" and "signal interceptors" sold illegally on the Internet. Criminals use these devices to interfere with the locking of car doors and steal cars or important items in cars. In addition, mutual interference between keyless entry systems of the same series of models also occurs from time to time.

(3) The driver needs to carry the vehicle key with him alone, and the convenience needs to be further improved.

(4) Based on a single judgment method for the key position, it may lead to accidents in special situations such as misoperation by occupants in the car.

(5) The function is single, and the vehicle key does not have any other extended functions except for opening and closing the car door.

UWB signal is a baseband impulse signal without carrier. First, this nanosecond-scale impulse signal has a very high time resolution. For example, when the duration of the impulse signal is set to τ=0.5ns, then according to the distance resolution equation Δr _c =(c/2)τ, substituting c=3×10 ⁸ m/s, you can get Δr _c =0.75 cm. It can be seen that UWB signals can achieve centimeter-level positioning; secondly, UWB signals disperse limited signal energy in an extremely wide frequency band, which is equivalent to white noise for other communication systems, and the power spectral density is lower than natural electronic noise. , it is almost impossible to be detected, so the security of the vehicle smart key is very good; again, the UWB signal uses intermittent baseband pulses with a very low duty cycle, and the power consumption of the system can be very low. If it is used in vehicles Smart keys can be used for several years or even ten years without changing the battery.

Contents of the invention

The purpose of the present invention is to overcome the defect that the positioning accuracy of the keyless entry system based on RSSI technology is not high, and propose a method and device for keyless entry, starting and locking of vehicles based on ultra-wideband, and use UWB signals to accurately locate the vehicle key: that is, by measuring The UWB signal emitted by the vehicle key radiates to the time difference of arrival (Time Difference Of Arrival TDOA) of multiple body antennas to calculate the spatial position of the key relative to the vehicle. At the same time, based on the UWB conformal antenna technology, the vehicle key is designed as the back plate shape of the mobile phone carried by the driver, and the vehicle key is used to replace the mobile phone back plate to realize the integration of the vehicle key and the mobile phone. And for each trigger action of the driver (opening, closing, starting, opening the trunk, closing the trunk) simultaneously detect the location of the vehicle key and the location information of the people in the car, and use the method of joint judgment to control the door lock, start system and alarm The system works. In addition, the function of the vehicle key is expanded to make it record the time of each engine start and stop, the corresponding mileage of each driving, the amount of fuel each time, and the average fuel consumption, etc., which are of interest to the driver; at the same time, the maintenance cycle information of the vehicle is stored. , and prompt the driver to maintain the vehicle according to the total mileage and total driving time. The present invention is realized through the following technical solutions.

UWB-based vehicle keyless entry, starting and locking device, including vehicle key, main controller, door lock sensor, start/stop button, seat sensor and body antenna array, door lock sensor, start/stop button, seat Both the sensor and the body antenna array are connected to the main controller through the body circuit; the body antenna array is used to communicate with the vehicle key, and the number of antennas in the body antenna array is greater than 3, one of which is the main antenna, and the others are Auxiliary antenna, the main antenna is used to radiate the UWB encrypted identity authentication signal and vehicle dynamic information signal generated by the main controller, the main antenna and all auxiliary antennas receive the UWB positioning signal sent by the vehicle key; the vehicle key is mainly used to receive the main controller The UWB encrypted identity authentication signal generated by the device performs identity authentication and sends a UWB positioning signal; the main controller is mainly used to generate the UWB encrypted identity authentication signal and receive the UWB positioning signal sent by the vehicle key, and to locate the vehicle key. It is used to control the work of the vehicle door lock, engine electronic lock, and alarm that the vehicle itself has; the door lock sensor is mainly used to sense the actions of opening/closing the door and opening/closing the trunk triggered by the driver, and generates a trigger signal to the main engine. The controller; the start/stop button is used to sense the driver's engine start action and generate a trigger signal to the main controller; the seat sensor is used to sense whether there is a person in the seat.

As a technical solution for further optimization of the UWB-based vehicle keyless entry, starting and locking device, the vehicle key includes a micro battery, an active crystal oscillator, a key-end microprocessor, a key-end UWB signal transceiver unit and a UWB conformal antenna , wherein the micro-battery is connected to the key-side microprocessor, the active crystal oscillator, and the key-side UWB signal transceiver unit; the active crystal oscillator is respectively connected to the micro-battery, the key-side microprocessor, and the key-side UWB signal transceiver unit to generate a Clock pulse; the microprocessor at the key end is also connected to the UWB signal transceiver unit at the key end, which is used to decode the received digitally encrypted identity authentication signal and compare it with the saved identity information for authentication. After the authentication is passed, the vehicle key is issued The digital positioning signal drives the UWB signal transceiver unit at the key end to generate a UWB positioning signal; the UWB signal transceiver unit at the key end is used to generate a corresponding UWB positioning signal according to the digital positioning signal transmitted from the microprocessor at the key end, and authenticate the received UWB encrypted identity After the signal is processed, the digitally encrypted identity authentication signal is transmitted to the key-end microprocessor, and the vehicle dynamic information signal is also received and transmitted to the key-end microprocessor; the UWB conformal antenna receives the UWB encrypted identity authentication signal sent by the body antenna, and Radiate the UWB positioning signal from the UWB signal transceiver unit at the key end.

As a technical solution for further optimization of the UWB-based vehicle keyless entry, starting and locking device, the vehicle key also includes a detachable memory card, which is connected to the key-end microprocessor, and the memory card is used to receive and save vehicle dynamic information , the vehicle dynamic information includes each engine start and stop time, the corresponding mileage each time, the fuel quantity and average fuel consumption each time, and the maintenance cycle information of the vehicle.

As a further optimized technical solution for the UWB-based vehicle keyless entry, starting and locking device, it also includes a display interface. One end of the display interface is connected to the main controller, and the other end is connected to the vehicle display for outputting seat sensors, door locks, etc. Sensors, door locks, engine electronic locks, alarms and the working status of the main controller.

As a technical solution for further optimization of the UWB-based vehicle keyless entry, starting and locking device, the main antenna is arranged at the center console inside the vehicle, and the auxiliary antenna is arranged at the door and the trunk door.

As a technical solution for further optimization of the UWB-based vehicle keyless entry, starting and locking device, the shape of the vehicle key is the back panel of a mobile phone, and the door lock sensor and the door handle are integrated.

The keyless vehicle entry method based on ultra-wideband of the present invention comprises the following steps:

(1) After the door lock sensor senses the driver's door opening action, it generates an unlock trigger signal and sends it to the main controller;

(2) The main controller generates a digital identity authentication signal after receiving the unlocking trigger signal, controls the internal UWB signal transceiver unit to generate a UWB encrypted identity authentication signal and radiates it through the main antenna, and controls the seat sensor to detect the position information of the person in the vehicle;

(3) When the vehicle key is within the set communication range, the UWB encrypted identity authentication signal is received and decoded, and then compared with the saved identity information for identity identification;

(4) After the identification is passed, the vehicle key sends out a UWB positioning signal;

(5) The main antenna and auxiliary antenna of the vehicle body respectively receive the UWB positioning signals sent by the vehicle key at different times, and transmit the UWB positioning signals received at different times to the main controller;

(6) The main controller calculates the spatial coordinates of the vehicle key by using a method based on the signal arrival time difference according to the UWB positioning signals received at the above-mentioned different times;

(7) The main controller judges the spatial position of the vehicle key relative to the vehicle body based on the above coordinates, and at the same time judges whether there are people in the car based on the detection information of the seat sensor.

(8) When the main controller judges that the vehicle key and personnel are in a legal and safe situation, that is, an abnormal situation, it sends an unlock command to control the unlocking of the door lock, and the driver can open the door to enter.

The keyless starting method for vehicles based on UWB of the present invention is characterized in that it comprises the following steps:

a. The engine is off, the driver presses the start/stop button, the start/stop button senses the driver's start trigger action, and generates a start trigger signal to the main controller, and the main controller sends out the start trigger signal after receiving the start trigger signal The digital identity authentication signal controls the internal UWB signal transceiver unit to generate a UWB encrypted identity authentication signal, and radiates it through the main antenna at the center console; at the same time, the main controller sends a seat detection command to control the seat sensor to detect whether there is anyone in the car and the location of the person;

b. The vehicle key decodes the received UWB encrypted identity authentication signal and compares it with the stored identity information for identification; if the vehicle key is a legal key, the identification passes and a UWB positioning signal is sent; if the vehicle key is an illegal key , the encrypted identity authentication signal cannot be decoded and identified;

c. The main controller judges the relative spatial position between the key and the car body according to the UWB positioning signal received by the car body antenna, and at the same time, the main controller judges whether there is anyone in the main driving position according to the signal detected by the seat sensor; when the main controller judges that the key is in the car and If there is no key outside the car, and at the same time it detects that there is someone in the main driving seat, it will issue a start command to drive the electronic engine lock to unlock, turn on the power and start the car; at the same time, the main controller will record the moment of this engine start and convert it into a corresponding UWB The signal is radiated through the main antenna at the center console, and the car key receives it and stores it in the memory card in the car key.

The keyless locking method for vehicles based on UWB of the present invention is characterized in that it comprises the following steps:

1) The driver turns off the engine, gets off the car and closes the door, and touches the lock button on the door handle to prompt the door to be locked; the door lock sensor inside the door handle senses the driver's action, generates a lock trigger signal and transmits it to the main controller, The main controller sends a digital identity authentication signal after receiving the locking trigger signal, controls the internal UWB signal transceiver unit to generate a UWB encrypted identity authentication signal, and radiates it through the main antenna at the center console; at the same time, the main controller sends a seat detection command , control the seat sensor to detect whether there is a person in the car and the location of the person;

2) The vehicle key decodes the received UWB encrypted identity authentication signal and compares it with the stored identity information for identification; if the vehicle key is a legal key, the identification passes and a UWB positioning signal is sent; if the vehicle key is an illegal key , the encrypted identity authentication signal cannot be decoded and identified;

3) The main controller judges the relative spatial position between the key and the car body according to the UWB positioning signal received by the car body antenna, and at the same time the main controller receives the seat sensor signal to judge whether there is anyone in any position in the car; There is no key, and at the same time, it detects that there is no one in any seat in the car, and then sends a locking command to drive the electronic engine lock and door lock to lock; at the same time, the main controller will record the current engine stop time, current mileage, current fuel volume and average The vehicle dynamic information of fuel consumption is converted into a corresponding UWB signal and radiated through the main antenna at the center console, and the car key receives it and stores it in the memory card in the vehicle key.

The above-mentioned ultra-broadband-based vehicle keyless entry, starting and locking method also includes an alarm process: when the main controller detects that any of the members in the vehicle or the key is abnormal, it determines that the corresponding trigger action is invalid and Immediately issue an alarm command to start the alarm; the abnormal situation and its corresponding triggering action include: no one is in the car but there is a key in the car, and the trigger action of opening the door is opened by a person outside the car; there is no one in the main driving position in the car but there are people in other positions, There is no key inside and outside the car, and the person in the car who is not in the main driver's seat presses the start button; there is no one in the main driver's seat in the car but there are people in other positions, there is no key outside the car but there is a key in the car, and the person in the car is not in the main driver's seat The person in the main driver’s seat does the triggering action of pressing the start button; there is someone in the main driver’s seat, but there is no key inside and outside the car, and the person in the main driver’s seat in the car does the triggering action of pressing the start button; The key, the person in the main driver's seat in the car does the trigger action of pressing the start button; there are people in the main driver's seat, and there are people in other seats, but there is no key inside and outside the car, and the person in the car makes the trigger action of pressing the start button; there is someone in the main driver's seat , There are also people in other positions, there is a key outside the car but no key in the car, and the personnel in the car do the trigger action of pressing the start button.

In the present invention, existing alarms, door lock motors, engine electronic locks and other equipment of the vehicle are connected with the main controller through the body circuit, and participate in work by receiving the driving instructions of the main controller.

The function of the vehicle key in the present invention can be expanded. In addition to receiving UWB encrypted identity authentication signals and performing identity authentication and sending UWB positioning signals, it can also receive and save each engine start and stop time, corresponding mileage each time, each time Information that is of interest to the driver, such as fuel volume and average fuel consumption, and vehicle maintenance cycle information, is collectively referred to as vehicle dynamic information.

Compared with the prior art, the present invention has the following advantages:

(1) The nanosecond-level UWB impulse signal adopted by the present invention has a very high distance resolution, and the detection method based on signal time difference of arrival (TDOA) can reach an accuracy of 2cm, even if two cars are close to each other or the key is close to the car door, It is also not easy to misjudgment.

(2) The UWB impulse signal bandwidth is very wide, and the spectrum without power peak makes its statistical characteristics close to Gaussian white noise. Artificial interference, cracking or copying based on the frequency domain is almost impossible to achieve, and the confidentiality is good.

(3) Using the method based on UWB conformal antenna, the key is integrated into the driver's mobile phone, the driver does not need to carry another key, and the convenience is greatly improved.

(4) A joint judgment method based on vehicle key position and occupant position information is adopted to better avoid accidents such as occupant misoperation.

(5) The function of the vehicle key is expanded, and the vehicle dynamic information such as the vehicle mileage, fuel volume, average fuel consumption, etc. that the driver is interested in but cannot be displayed by the existing vehicle instrument is saved for the driver's reference.

Description of drawings

Figure 1 is a structural block diagram of the body part that realizes keyless entry, start and lock of the vehicle

Figure 2 is a block diagram of the internal structure of the vehicle key to realize keyless entry, start and lock of the vehicle

Figure 3 is a block diagram of the internal structure of the UWB signal transceiver unit inside the vehicle key and the main controller

Figure 4 is an example of the vehicle key conforming to the back panel of the mobile phone

Figure 5 is a schematic diagram of the layout of each unit to realize the keyless entry, start and lock of the vehicle

Figure 6 is the overall work flow chart for realizing vehicle keyless entry, starting and locking

Detailed ways

The specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

As shown in FIG. 1 , it is a block diagram of the overall structure of the body part of the present invention to realize keyless entry, start and lock. It consists of four parts: one is the main controller, including the main control MCU, the clock and the UWB signal transceiver unit of the main control terminal. Among them, the main control MCU mainly processes the trigger signal input by the door lock sensor, start/stop button, seat sensor and the digital positioning signal input by the UWB signal transceiver unit of the main control terminal, and sends out driving instructions to control the door lock motor and electronic engine lock. , alarm and other external devices, and also generate or record engine start/stop time, each mileage, fuel consumption and other vehicle dynamic information; the clock is mainly responsible for generating nanosecond-level reference square wave signals; the main control terminal UWB signal transmission and reception The unit is mainly responsible for generating UWB encrypted identity authentication signals and processing UWB positioning signals from the body antenna to obtain digital positioning signals and transmit them to the main control MCU. The second is various sensors, including seat sensors, door lock sensors, and start/stop buttons. The seat sensors mainly detect whether there are people in the car and their positions; the door lock sensors and start/stop buttons are mainly responsible for sensing the driver's trigger action and generating The corresponding trigger signal is input to the main controller. The third is each executive mechanism, including the alarm, door lock motor and electronic engine lock, which mainly executes the output instructions of the main controller. The fourth is other external equipment, including body antenna, power supply, display interface, etc. The power supply is only responsible for supplying power to the main controller, and the rest of the equipment is powered by the on-board 12v battery. The display interface is connected with the vehicle display to display the status of the entire keyless entry and start device.

The main controller, door lock sensor, start/stop button, seat sensor, display interface and body antenna array are all arranged on the body. The door lock sensor (integrated with the door handle), start/stop button, seat sensor, display interface and body antenna array are all connected to the main controller through the body circuit. The composition of the main controller includes a microprocessor (main control MCU), a clock and a UWB signal transceiving unit (a master control end UWB signal transceiving unit), and these three are connected to each other in pairs. The functions of the main controller include generating UWB encrypted identity authentication signals and receiving UWB positioning signals, and driving external devices such as vehicle door locks, engine electronic locks, and alarm systems to work. Among them, the main control MCU mainly processes the trigger signal input by the door lock sensor, start/stop button, seat sensor and the digital positioning signal input by the UWB signal transceiver unit of the main control terminal, calculates the spatial position of the vehicle key, and issues a drive command to control The door lock motor, electronic engine lock, alarm and other external devices work; the clock is responsible for generating nanosecond-level pulse repetition frequency (reference square wave signal); the UWB signal transceiver unit of the master control terminal is mainly responsible for generating UWB encrypted identity authentication signals and The UWB positioning signal from the vehicle body antenna is processed to obtain a digital positioning signal, and then transmitted to the main control MCU for precise positioning of the vehicle key: there are n total body antennas, because the space distance between the n body antennas and the vehicle key is not equal, so For the UWB positioning signal sent by the vehicle key, n body antennas record n specific arrival moments. However, one time difference of arrival (TDOA) can be determined for every two arrival times. In this way, a total of n(n-1)/2 TDOAs can be determined for n arrival times. And because each TDOA determines a space hyperboloid, theoretically the intersection of three space hyperboloids can determine a space coordinate point (vehicle key position), so as long as n>3, according to this n(n-1)/ Only 2 TDOAs can solve the vehicle key position very accurately. The door lock sensor mainly senses the action triggered by the driver (opening/closing the door, opening/closing the trunk) and generates a trigger signal to the main controller. The start/stop button is mainly to sense the driver's action of starting the engine and generate a trigger signal to the main controller (in fact, turning off the engine is also the driver's trigger action, but because it does not need to involve the positioning of the vehicle key, it will not be considered here) . Seat sensors are respectively arranged under each seat in the car to sense whether there is a person in the seat. The display interface is connected with the on-board display through a data line, and outputs the status of devices such as sensors, door locks, engine electronic locks, alarms, and the main controller. The total number of body antennas is more than 3, one of which is the main antenna, which is arranged at the position of the internal center console, and the others are auxiliary antennas, which are respectively arranged near the car door and the trunk door. The UWB encrypted identity authentication signal generated by the main controller and the engine start Vehicle dynamic information signals such as time and stop time are only radiated through the main antenna, while all main antennas and auxiliary antennas receive the UWB positioning signal sent by the vehicle key.

As shown in Figure 2, it is a block diagram of the internal structure of the vehicle key, including a micro battery, a key-side microprocessor, an active crystal oscillator, a key-side UWB signal transceiver unit, a conformal antenna and a microSD card. The micro battery mainly completes the power supply; the key-side microprocessor mainly decodes and authenticates the digitally encrypted identity authentication signal and sends a digital positioning signal to the key-side UWB signal transceiver unit; The digital positioning signal generates the corresponding UWB positioning signal, and processes the UWB encrypted identity authentication signal from the vehicle body to obtain a digitally encrypted identity authentication signal; the UWB conformal antenna mainly receives the UWB encrypted identity authentication signal and radiates the UWB positioning signal. In addition, it also receives other vehicle dynamic information signals and transmits them to the key-side microprocessor; the microSD card saves the vehicle dynamics that the driver is interested in, such as the time of each engine start and stop, the corresponding mileage of each trip, the amount of fuel each time, and the average fuel consumption. Information and maintenance interval information for the vehicle. When the total driving mileage or total driving time of the vehicle reaches the specified value of the maintenance cycle, the microprocessor at the key end sends a prompt message and transmits it to the vehicle body display, so that the driver can maintain the vehicle in time.

As shown in FIG. 3 , it is a block diagram of the internal structure of an embodiment of the UWB signal transceiving unit. The composition of the UWB signal transceiver unit includes a pulse generator, a pulse position modulator, a power amplifier, a low-noise amplifier, a radio frequency filter, a multiplier, a low-pass filter, and a sampling/detector. The generation process of the UWB signal is: the pulse generator receives the external reference square wave signal to generate the basic UWB signal; the basic UWB signal is input into the pulse position modulator, and the pulse position modulator performs pulse position modulation on the basic UWB signal according to the input digital signal of the MCU After that, the modulated UWB signal is generated; the modulated UWB signal is amplified by the input power amplifier and radiated out by the UWB antenna. The receiving process of the UWB signal is: the signal is received by the UWB antenna, and then input to the low noise amplifier, radio frequency filter and multiplier in turn. At the same time, the multiplier receives the basic UWB signal input by the pulse generator, multiplies the two signals and inputs them to the low-pass filter, and the filtered signal is input to the sampling/detector for sampling and detection, and a processable digital signal is input to the MCU.

As shown in Fig. 4a-Fig. 4c, it is an embodiment of the conformal shape between the vehicle key and the back panel of the mobile phone according to the present invention. Fig. 4a is a plan view of the outside of the vehicle key, where a radiation patch 401 and a corresponding ground 402 together form a complete UWB antenna. Its specific shape is: the radiation patch 401 is a semicircle composed of two symmetrical quarter circles with a rectangular space in the middle. The shape of the ground 402 is a semicircle symmetrical up and down with the radiating patches 401 plus a rectangular space extending between the radiating patches 401 . A gradual groove is formed between the ground 402 and its symmetrical semicircular radiation patch 401. The minimum width gap of the gradual groove is greater than 0.1mm, which realizes the transformation of the impedance of the UWB antenna and the characteristic impedance of the air, and ensures that the UWB antenna meets the FCC’s spectrum masking standard. A rectangle is added between the two quarter circles to increase the current path and expand the low-frequency bandwidth of the UWB antenna. Fig. 4b is a plan view of the inside of the vehicle key, in which a micro battery 403, an active crystal oscillator 404, a key-side microprocessor 405, a key-side UWB signal transceiving unit 406 and a microSD card 407 are embedded inside a substrate 408. Fig. 4c is an elevation view of a vehicle key, and the substrate 408 is an ordinary FR4 substrate with a thickness not exceeding 1mm. In this way, the length L of the vehicle key is 20mm, the width W is 20mm, and the thickness T is 1mm, which can conform to most mobile phone backplanes.

As shown in FIG. 5 , it is a schematic diagram of an embodiment of the arrangement of various units of the vehicle body to realize the keyless entry, start and lock of the vehicle according to the present invention. The door lock sensor 501 (integrated with the door handle), the start/stop button 502, the seat sensor 503, the display interface and the body antenna array 504 are all connected to the main controller 505 through the body circuit. The main controller is arranged under the hood, the main antenna is arranged at the center console, and the other five antennas are arranged near the door. There are 5 door lock sensors in total, which are arranged in each door handle and trunk door handle respectively. There are a total of 5 seat sensors, which are respectively arranged under the five seats in the car to sense whether there are people in the seat.

The present invention adopts the principle of multi-point ranging difference space positioning based on signal time difference of arrival (Time Difference Of Arrival TDOA). The set of points with the same distance difference to two points forms a hyperboloid, so more than 4 antennas can be calibrated on the body (in fact, 6 antennas are arranged on the body for accurate positioning), and the target (vehicle key) for precise positioning. The basic equation is as follows: Suppose the position of the target (vehicle key) is (x, y, z), and the positions of n antennas are ( _xi , _y , zi ₎ (i=0, 1, 2, 3, ..., n-1 ), let one of them be the main antenna, which is the origin of the positioning coordinates. n signal arrival times ti (i=0, 1, 2, 3, . . . , n−1) can be recorded by n antennas. A time difference is determined every two arrival moments, thus n(n-1)/2 time differences τ _jk (j=0,1,2,3,...,n-1; k=1,2, 3, . . . , n-1; j<k). A ternary nonlinear equation can be determined for each time difference:

$\sqrt{{(x_j-x)}^2+{({\mathrm{the\; y}}_j-\mathrm{the\; y})}^2+{(z_j-z)}^2}-\sqrt{{(x_k-x)}^2+{({\mathrm{the\; y}}_k-\mathrm{the\; y})}^2+{(z_k-z)}^2}={\mathrm{c\&tau;}}_{\mathrm{jk}}$ (Formula 1)

(j=0, 1, 2, 3,..., n-1; k=1, 2, 3,..., n-1; j<k, c is the propagation speed of electromagnetic waves in the air). Therefore, theoretically, the three above-mentioned equations can solve the position (x, y, z) of the target (vehicle key). In practice, the analytical solutions of nonlinear equations are difficult to find. Therefore, the present invention adopts a two-step method to simplify the above equations into linear equations and solve them by an iterative method. When the accuracy is satisfied, the solution speed is improved and the hardware cost is reduced. details as follows:

Step 1: Assuming that the distance from the antenna (x ₀ , y ₀ , z ₀ ) that first received the signal to the target (vehicle key) is known and set to r, the equation becomes x, y, z with respect to r Linear function:

$(x_k-x_0)x+({\mathrm{the\; y}}_k-{\mathrm{the\; y}}_0)\mathrm{the\; y}+(z_k-z_0)z=-{\mathrm{c\&tau;}}_{0k}r+\frac{1}{2}[({x_k}^2+{{\mathrm{the\; y}}_k}^2+{z_k}^2)-({x_k}^2+{{\mathrm{the\; y}}_k}^2+{z_k}^2)-c^2{\mathrm{\&tau;}}_{0k}^2]$ (Formula 2)

(k=1, 2, 3, ..., n-1) In addition, three antenna coordinates (x ₁ , y ₁ , z ₁ ), (x ₂ , y ₂ , z ₂ ), (x ₃ , y ₃ , z ₃ ) and get three target arrival time differences τ ₀₁ , τ ₀₂ , τ ₀₃ , and express the obtained three equations in the form of matrix:

$\left[\begin{array}{ccc}{x}_1-x_0& {\mathrm{the\; y}}_1-{\mathrm{the\; y}}_0& z_1-z_0\\ x_2-x_0& {\mathrm{the\; y}}_2-{\mathrm{the\; y}}_0& z_2-z_0\\ x_3-x_0& {\mathrm{the\; y}}_3-{\mathrm{the\; y}}_0& z_3-z_0\end{array}\right]\left[\begin{array}{c}x\\ \mathrm{the\; y}\\ z\end{array}\right]=\left[\begin{array}{c}-{\mathrm{c\&tau;}}_{01}r+\frac{1}{2}[({x_1}^2+{{\mathrm{the\; y}}_1}^2+{z_1}^2)-({x_0}^2+{{\mathrm{the\; y}}_0}^2+{z_0}^2)-c^2{\mathrm{\&tau;}}_{01}^2]\\ -{\mathrm{c\&tau;}}_{02}r+\frac{1}{2}[({x_2}^2+{{\mathrm{the\; y}}_2}^2+{z_2}^2)-({x_0}^2+{{\mathrm{the\; y}}_0}^2+{z_0}^2)-c^2{\mathrm{\&tau;}}_{02}^2]\\ -{\mathrm{c\&tau;}}_{03}r+\frac{1}{2}[({x_3}^2+{{\mathrm{the\; y}}_3}^2+{z_3}^2)-({x_0}^2+{{\mathrm{the\; y}}_0}^2+{z_0}^2)-c^2{\mathrm{\&tau;}}_{03}^2]\end{array}\right]$ (Formula 3)

If the above equation is abbreviated as Ax=B, the least square solution of x can be obtained as: x=(A ^T A) ^-1 A ^T B. Substituting the solution of x (that is, the solution of x, y, z) into the original equation about r (Formula 2), the quadratic equation of r can be obtained, and the two values of r can be solved. According to the time difference, a false value is removed, Substituting the value of r into the linear equation system (formula 3), the estimated value (x _v , y _v , z _v ) of the coordinates of the target (vehicle key) can be obtained.

Step 2: use Taylor series method for iterative solution to improve the accuracy. Still assume that the real position of the target (vehicle key) is (x, y, z). The time difference detected by the kth antenna relative to the main antenna (the origin of coordinates) is τ _k , the true value of the time difference is μ _k , and the measurement error is e _k . Assume that the measurement error obeys the expectation of 0, and the covariance matrix is a Gaussian distribution of R. Then the target coordinate equation can be expressed as:

$\sqrt{{(x_k-x)}^2+{({\mathrm{the\; y}}_k-\mathrm{the\; y})}^2+{(z_k-z)}^2}-\sqrt{{(x_0-x)}^2+{({\mathrm{the\; y}}_0-\mathrm{the\; y})}^2+{(z_0-z)}^2}={\mathrm{c\&mu;}}_k=c({\mathrm{\&tau;}}_k-e_k)$ (Formula 4)

Express the above equation as a function f _k (x, y, z, x _k , y _k , z _k ) of (x, y, z):

$f_k(x,\mathrm{the\; y},z,x_k,{\mathrm{the\; y}}_k,z_k)=\frac{\sqrt{{(x_k-x)}^2+{({\mathrm{the\; y}}_k-\mathrm{the\; y})}^2+{(z_k-z)}^2}-\sqrt{{(x_0-x)}^2+{({\mathrm{the\; y}}_0-\mathrm{the\; y})}^2+{(z_0-z)}^2}}{c}={\mathrm{\&tau;}}_k-e_k$ (Formula 5)

The specific steps of the Taylor series positioning method are as follows:

a. According to the estimated value (x _v , y _v , z _v ) obtained in the first step, the expression of the error can be obtained: δ _x =xx _v , δ _y =yy _v , δ _z =zz _v .

b. Expand f _k (x, y, z, x _k , y _k , z _k ) at the initial estimated position (x _v , y _v , z _v ) with Taylor series, and ignore the quadratic and high-order terms:

$f_{\mathrm{kv}}(x_v.{\mathrm{the\; y}}_v,z_v,x_k,{\mathrm{the\; y}}_k,z_k)+\frac{{\&PartialD;f}_k}{\&PartialD;x}{|}_{x_v,{\mathrm{the\; y}}_v,z_v}{\mathrm{\&delta;}}_x+\frac{{\&PartialD;f}_k}{\&PartialD;\mathrm{the\; y}}{|}_{x_v,{\mathrm{the\; y}}_v,z_v}{\mathrm{\&delta;}}_{\mathrm{the\; y}}+\frac{{\&PartialD;f}_k}{\&PartialD;z}{|}_{x_v,{\mathrm{the\; y}}_v,z_v}{\mathrm{\&delta;}}_z\&ap;{\mathrm{\&tau;}}_k-e_k$ (Formula 6)

Among them (k=1, 2...n), and f _kv (x _v , y _v , z _v , x _k , y _k , z _k ) is a constant term, which can be moved to the right side of the equal sign, and the above equation Represented in matrix form:

$\left[\begin{array}{ccc}\frac{{\&PartialD;f}_1}{\&PartialD;x}& \frac{{\&PartialD;f}_2}{\&PartialD;\mathrm{the\; y}}& \frac{{\&PartialD;f}_1}{\&PartialD;z}\\ \frac{{\&PartialD;f}_2}{\&PartialD;x}& \frac{{\&PartialD;f}_2}{\&PartialD;\mathrm{the\; y}}& \frac{{\&PartialD;f}_2}{\&PartialD;z}\\ m& m& m\\ \frac{{\&PartialD;f}_{\mathrm{no}}}{\&PartialD;x}& \frac{{\&PartialD;f}_{\mathrm{no}}}{\&PartialD;\mathrm{the\; y}}& \frac{{\&PartialD;f}_{\mathrm{no}}}{\&PartialD;z}\end{array}\right]\left[\begin{array}{c}{\mathrm{\&delta;}}_x\\ {\mathrm{\&delta;}}_{\mathrm{the\; y}}\\ {\mathrm{\&delta;}}_z\end{array}\right]\&ap;\left[\begin{array}{c}{\mathrm{\&tau;}}_1-e_1-f_{1v}(x_v,{\mathrm{the\; y}}_v,z_v,x_1,{\mathrm{the\; y}}_1,z_1)\\ {\mathrm{\&tau;}}_2-e_2-f_{2v}(x_v,{\mathrm{the\; y}}_v,z_v,x_2,{\mathrm{the\; y}}_2,z_2)\\ m\\ {\mathrm{\&tau;}}_{\mathrm{no}}-e_{\mathrm{no}}-f_{\mathrm{nv}}(x_v,{\mathrm{the\; y}}_v,z_v,x_{\mathrm{no}},{\mathrm{the\; y}}_{\mathrm{no}},z_{\mathrm{no}})\end{array}\right]$ (Formula 7)

It can be abbreviated as: Aδ≈B. In the present invention, the number of antennas n=6>3, so the above-mentioned matrix equation is full rank, so the least squares estimated value of δ is: δ=(A ^T R ^-1 A) ^-1 A ^T R ^-1 B .

N表示迭代次数。开始进行迭代运算：x_v←x_v+δ_x；y_v-y_v+δ_y；z_v-z_v-δ_z c. Selection criteria

N represents the number of iterations. Start iterative operation: x _v ←x _v +δ _x ; y _v -y _v +δ _y ; z _v -z _v -δ _z

d. Compare the criterion ε with the given threshold value ε _0. When ε>ε ₀ , repeat steps b and c until ε<ε ₀ , then stop the iteration. The final target (vehicle key) position is: $\hat{x}=x_v+{\mathrm{\&delta;}}_x;$ $\widehat{\mathrm{the\; y}}={\mathrm{the\; y}}_v+{\mathrm{\&delta;}}_{\mathrm{the\; y}};$ $\hat{z}=z_v+{\mathrm{\&delta;}}_z.$

As shown in Figure 6, it is the overall work flow chart of the present invention to realize the keyless entry, start and lock of the vehicle; its basic work procedure is: for each trigger action of the driver, the main controller will send out two instructions first , and accept two signals, and then control the three actuators according to the logic table shown in Table 1. The driver's trigger actions can be divided into three categories: door opening (including individual doors or the trunk door), door closing and activation. The two commands issued by the main controller are to control the UWB signal transceiver unit of the main control terminal to send UWB encrypted identity authentication signals and to control the seat sensor to detect whether there are people in the car and their positions. The two signals received by the main controller are the vehicle Key location information and vehicle occupant location information. Finally, the main controller sends corresponding drive commands according to the logic table to control the door lock motor, engine electronic lock and alarm system according to the two pieces of information. In the following, we will describe the flow chart and the 16 situations in Table 1 one by one.

Situation 1: There is no one in the car, and there is no key inside or outside the car. This is a common situation where the driver locks the car and leaves the vehicle, the output of the system is that the doors are locked, the electronic engine lock is locked, and the vehicle does not alarm.

Situation 2: There is no one in the car, but there is a key in the car. This is an illegal situation where the driver or other occupants leave the key in the vehicle, and the output of the keyless system is that the doors cannot be locked, the electronic engine lock is locked, and the vehicle alarms. But the driver can artificially disarm the alarm and leave a key in the car on purpose.

Situation 3: There is no one in the car, but there are keys outside the car. This is a normal situation, that is, the driver opens the door normally, the output of the keyless system is unlocked, the electronic engine lock is locked, and the vehicle does not alarm.

Situation 4: There is no one in the car, and there are keys inside and outside the car. This is a relatively rare legal situation, that is, there is one key in the car, the driver uses another key to open the door normally, the output of the keyless system is unlocked, the electronic engine lock is locked, and the vehicle does not alarm.

Situation 5: There is no one in the main driving position in the car, but there are people in other positions, and there is no key inside or outside the car. Often, this is a legal situation where the driver leaves the vehicle to run errands, leaving the occupants in the vehicle. However, when there are no adults and only children in the occupants, this is an extremely dangerous situation. If the vehicle is automatically locked and the driver does not come back for a long time, dangerous situations such as lack of oxygen in the vehicle will occur. Such an example is in reality. found in. If the vehicle is not automatically locked, children may leave the vehicle by themselves and cause other dangers. Therefore, in the keyless entry and starting device of the present invention, it is considered that this is an illegal situation, and the output car door is unlocked, the electronic engine lock is locked, and the vehicle reports to the police. Of course, the driver manually removes the alarm after judging, and can handle it flexibly.

Case 6: This is similar to case 5, so the output is the same.

Situation 7: There is no one in the main driver's seat and someone in the other seat, and there is a key outside the car. This condition indicates that the driver is near the vehicle, so the output is that the doors are unlocked, the electronic engine lock is locked, and the vehicle does not alarm.

Case 8: This is similar to case 7, so the output is the same.

Situation 9: There is someone in the main driver's seat, but there is no key inside or outside the car. This is an illegal situation, indicating that someone has entered the car without identity authentication, so the output is the door is locked, the electronic engine is locked, and the vehicle alarms.

Situation 10: There is someone in the main driver's seat, and there is a key in the car. This is the normal driver's pre-start situation, the output is the door is unlocked, the electronic engine lock is unlocked, and the vehicle does not alarm.

Situation 11: There is someone in the main driver's seat, there is no key inside the car but there is a key outside the car. This is a relatively rare illegal situation, usually when the driver drops the vehicle key outside the car. So the output is door unlock, electronic engine lock lock, vehicle alarm. Of course, it is also possible that the driver gave his mobile phone to people outside the car, at this time the driver can manually cancel the alarm.

Situation 12: There are people in the main driver's seat and no one in the other seats, and there are keys inside and outside the car. It is a legal situation to indicate that the person carrying the other key is near the vehicle, and the output is that the doors are unlocked, the electronic engine lock is unlocked, and the vehicle does not alarm.

Situation 13: There are people in the main driver's seat and other seats, but there are no keys inside or outside the car. This is an illegal situation, indicating that someone has entered the car without authentication, and the output is the door is locked, the electronic engine lock is locked, and the vehicle alarms.

Situation 14: There are people in the main driver's seat and other seats, and there are keys in the car. This is the most common legal situation, the output is the door is unlocked, the electronic engine lock is unlocked, and the vehicle does not alarm.

Situation 15: There are people in the main driver's seat and people in other positions, and there are keys outside the car but no keys in the car. This is an illegal situation similar to case 11, so the output is the same as case 11.

Situation 16: There are people in the main driver's seat and other people, and there are keys inside and outside the car. This is a legal case similar to Case 12, so the output is the same as Case 12.

Table 1: Access control, start and alarm system working logic relationship table

Claims (10)

1. A vehicle keyless entry, starting and locking device based on ultra-wideband, characterized in that it includes a vehicle key, a main controller, a door lock sensor, a start/stop button, a seat sensor and a body antenna array, a door lock sensor, a start/stop The stop button, the seat sensor and the body antenna array are all connected to the main controller through the body circuit; the body antenna array is used to communicate with the vehicle key, and the number of antennas in the body antenna array is greater than 3, one of which is The main antenna, the others are auxiliary antennas, the main antenna is used to radiate the UWB encrypted identity authentication signal generated by the main controller and the vehicle dynamic information signal, the main antenna and all auxiliary antennas receive the UWB positioning signal sent by the vehicle key; the vehicle key mainly It is used to receive the UWB encrypted identity authentication signal generated by the main controller and perform identity authentication and send the UWB positioning signal; the main controller is mainly used to generate the UWB encrypted identity authentication signal and receive the UWB positioning signal sent by the vehicle key, and the vehicle key Positioning is also used to control the vehicle door locks, engine electronic locks, and alarms that the vehicle itself has; the door lock sensor is mainly used to sense the actions of opening/closing the door and opening/closing the trunk triggered by the driver, and generates The trigger signal is sent to the main controller; the start/stop button is used to sense the driver's action of starting the engine and generates a trigger signal to be sent to the main controller; the seat sensor is used to sense whether there are people in the seat. 2. The UWB-based vehicle keyless entry, starting and locking device according to claim 1, wherein the vehicle key includes a micro battery, an active crystal oscillator, a key-side microprocessor, a key-side UWB signal transceiver unit and UWB conformal antenna, wherein the micro-battery is connected to the key-side microprocessor, active crystal oscillator, and key-side UWB signal transceiver unit; the active crystal oscillator is respectively connected to the micro-battery, key-side microprocessor, and key-side UWB signal transceiver unit, Used to generate a clock pulse; the key-side microprocessor is also connected to the key-side UWB signal transceiver unit, which is used to decode the received digitally encrypted identity authentication signal and compare it with the saved identity information for authentication. After the authentication is passed , sending out the digital positioning signal of the vehicle key to drive the UWB signal transceiver unit at the key end to generate a UWB positioning signal; After the UWB encrypted identity authentication signal is processed, the digital encrypted identity authentication signal is transmitted to the key-end microprocessor, and the vehicle dynamic information signal is also received and transmitted to the key-end microprocessor; the UWB conformal antenna receives the UWB encrypted identity sent by the body antenna Authentication signal, and radiate the UWB positioning signal from the UWB signal transceiver unit at the key end. 3. According to the UWB-based vehicle keyless entry, starting and locking device according to claim 2, it is characterized in that the vehicle key also includes a detachable memory card, the memory card is connected to the key terminal microprocessor, and the memory card is used to receive And save the dynamic information of the vehicle, the dynamic information of the vehicle includes each engine start and stop time, the corresponding mileage each time, the fuel quantity and average fuel consumption each time, and the maintenance cycle information of the vehicle. 4. The ultra-broadband-based vehicle keyless entry, starting and locking device according to claim 1, characterized in that it also includes a display interface, one end of the display interface is connected to the main controller, and the other end is connected to the vehicle display for output socket Seat sensor, door lock sensor, door lock, engine electronic lock, alarm and the working status of the main controller. 5. The vehicle keyless entry and start device based on ultra-wideband positioning according to any one of claims 1 to 4, characterized in that the main antenna is arranged at the position of the center console inside the car, and the auxiliary antenna is arranged at the door and the trunk at the door. 6. The ultra-broadband-based vehicle keyless entry, starting and locking device according to claim 5, characterized in that the shape of the vehicle key is the shape of the back panel of a mobile phone, and the door lock sensor and the door handle are integrated. 7. The vehicle keyless entry method based on ultra-wide band, is characterized in that comprising the following steps: (1) After the door lock sensor senses the driver's door opening action, it generates an unlock trigger signal and sends it to the main controller; (2) The main controller generates a digital identity authentication signal after receiving the unlock trigger signal, controls the internal UWB signal transceiver unit to generate a UWB encrypted identity authentication signal and radiates it through the main antenna, and controls the seat sensor to detect the position information of the occupants in the vehicle; (3) When the vehicle key is within the set communication range, the UWB encrypted identity authentication signal is received and decoded, and then compared with the saved identity information for identity identification; (4) After the identification is passed, the vehicle key sends out a UWB positioning signal; (5) The main antenna and auxiliary antenna of the vehicle body respectively receive the UWB positioning signals sent by the vehicle key at different times, and transmit the UWB positioning signals received at different times to the main controller; (6) The main controller calculates the spatial coordinates of the vehicle key based on the UWB positioning signals received at different times above, using a method based on the signal arrival time difference; (7) The main controller judges the spatial position of the vehicle key relative to the body according to the above coordinates, and at the same time according to the seat sensor The detection information judges whether there is a person in the car, and if there is a person, it is necessary to judge whether the person in the car is in the driving position or not; (8) When the main controller judges that the vehicle key and personnel are in a legal and safe situation, that is, an abnormal situation, it sends an unlock command to control the unlocking of the door lock, and the driver can open the door to enter. 8. The vehicle keyless start method based on ultra-wide band, it is characterized in that comprising the steps: The engine is off, the driver presses the start/stop button, the start/stop button senses the driver's start trigger action, and generates a start trigger signal to the main controller, and the main controller sends a digital identity after receiving the start trigger signal The authentication signal controls the internal UWB signal transceiver unit to generate a UWB encrypted identity authentication signal, which is radiated out through the main antenna at the center console; at the same time, the main controller sends a seat detection command to control the seat sensor to detect whether there are people and people in the car s position;

The vehicle key decodes the received UWB encrypted identity authentication signal and compares it with the stored identity information for identification; if the vehicle key is a legal key, the identification passes and a UWB positioning signal is sent; if the vehicle key is an illegal key, then Unable to decode and identify encrypted identity authentication signals;

The main controller judges the relative spatial position between the key and the vehicle body according to the UWB positioning signal received by the vehicle body antenna, and at the same time, the main controller judges whether there is anyone in the main driving position according to the signal detected by the seat sensor; If there is no key, and at the same time it is detected that there is someone in the main driving seat, it will issue a start command to drive the electronic engine lock to unlock, turn on the power and start the car; at the same time, the main controller will record the moment of this engine start and convert it into a corresponding UWB signal to pass The main antenna at the center console radiates out, and the car key receives it and stores it in the memory card in the car key. 9. The vehicle keyless locking method based on ultra-wide band, it is characterized in that comprising the steps: 1) The driver turns off the engine, gets out of the car and closes the door, and touches the lock button on the door handle to prompt the door to be locked; the door lock sensor in the door handle senses the driver's action, generates a lock trigger signal and transmits it to the main controller, The main controller sends a digital identity authentication signal after receiving the locking trigger signal, controls the internal UWB signal transceiver unit to generate a UWB encrypted identity authentication signal, and radiates it through the main antenna at the center console; at the same time, the main controller sends a seat detection command , control the seat sensor to detect whether there is a person in the car and the position of the person; 2) The vehicle key decodes the received UWB encrypted identity authentication signal and compares it with the stored identity information for identification; if the vehicle key is a legal key, the identification passes and a UWB positioning signal is sent; if the vehicle key is an illegal key , the encrypted identity authentication signal cannot be decoded and identified; 3) The main controller judges the relative spatial position between the key and the car body according to the UWB positioning signal received by the car body antenna, and at the same time the main controller receives the seat sensor signal to judge whether there is any person in the car; when the main controller judges that the key is outside the car but inside the car There is no key, and at the same time, it detects that there is no one in any seat in the car, and then sends a locking command to drive the electronic engine lock and door lock to lock; at the same time, the main controller will record the current engine stop time, current mileage, current fuel volume and average The vehicle dynamic information of fuel consumption is converted into a corresponding UWB signal and radiated through the main antenna at the center console, and the car key receives it and stores it in the memory card in the vehicle key. 10. The method according to claims 7-9, characterized in that it also includes an alarm process: when the main controller detects that any of the members in the car or the key is abnormal, it determines that the corresponding trigger action is invalid and sends out an alarm immediately. The alarm command starts the alarm; the abnormal situation and its corresponding trigger actions include: there is no one in the car but there is a key in the car, the trigger action of people outside the car opening the door; there is no one in the main driving position in the car but there are people in other positions, There is no key, and the person who is not in the main driver's seat in the car does the trigger action of pressing the start button; there is no one in the main driver's seat in the car but there are people in other positions, there is no key outside the car but there is a key in the car, and the person in the car is not in the main driver's seat. The trigger action of pressing the start button; there is a person in the main driver's seat, but there is no key inside and outside the car, and the person in the main driver's seat in the car performs the trigger action of pressing the start button; there is a person in the main driver's seat, there is no key in the car but there is a key outside the car, The person in the main driver's seat in the car performs the trigger action of pressing the start button; there are people in the main driver's seat and other people, but there is no key inside and outside the car, and the person in the car performs the trigger action of pressing the start button; there are people in the main driver's seat, and others There are also people in the position, there is a key outside the car but no key in the car, and the people in the car do the trigger action of pressing the start button.

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