Summary of the invention
The invention provides a kind of car crane monitoring system based on MHL technology, by Bluetooth wireless technology, portable equipment and car-mounted terminal are connected as a single entity and monitor, not only simplify the complexity of vehicle performance, lifting automobile brand hommization aspect is had great importance, and has effectively saved the limited system resource overhead of car-mounted terminal.
Technical scheme of the present invention is: a kind of car crane monitoring system based on MHL technology, and comprise car machine and mobile phone, described mobile phone comprises: HMI human-computer interaction module: be used for sending request order to car-mounted terminal, or initiatively receive pushed information; Bluetooth communication module: the information exchange medium of mobile phone and car machine, mobile phone carries out information exchange by bluetooth communication module and car machine; Described car machine comprises: ECU module: ECU module receives the data of mobile phone or order, and response instruction, performs mobile phone command or sends order to mobile phone, realizes mobile phone and car machine is interconnected; Wireless application transceiver module: the information exchange medium of car machine, car machine connects mobile phone by wireless application transceiver module; CAN-USB signal transmitting and receiving module: CAN-USB module, as Che Ji signal centre, completes the transmission of the data parameters of vehicle mounted electrical apparatus.Described car machine also comprises MHL module, and the audio, video data with screen mirror image is transferred to car machine by MHL module by the mobile devices such as mobile phone.Described car machine also comprises vehicle-mounted human-computer interaction module, and car machine controls mobile phone or the instruction of response mobile phone by vehicle-mounted human-computer interaction module.Described vehicle-mounted human-computer interaction module comprises physical button, touch-screen button or Voice command mode.Described bluetooth communication module is the frequency hop sequences selection algorithm adopting the iterative type block cipher based on Advanced Encryption Standard to construct, and the hamming correlation of described frequency hop sequences selection algorithm determines, can be expressed from the next:
In formula, X, Y are the mould that frequency hop sequences 0≤τ≤N-1, N represents (i+ τ).Described bluetooth communication module adopts the error correction algorithm merging interweaving encoding and FEC.
The present invention has following good effect: the present invention is intended to effective wireless connections of specification smart mobile phone and onboard system, and forms good Consumer's Experience.Adopt this standard carry out mobile phone car machine interconnected time, can realize the installation mobile phone of application specific software and the double-direction control of car machine, make user in vehicle traveling process, without looking at mobile phone screen, touch mobile phone screen or operating handset button, only need to control mobile phone by the physical button on vehicle-mounted or voice command, comprise answer/make phone, media play, GPS navigation etc., also can complete the functions such as vehicle backing backsight, vehicle data collection, failure diagnosis, remote monitoring simultaneously.
Contrast accompanying drawing below, by the description to embodiment, the specific embodiment of the present invention is as the effect of the mutual alignment between the shape of involved each component, structure, each several part and annexation, each several part and operation principle, manufacturing process and operation using method etc., be described in further detail, have more complete, accurate and deep understanding to help those skilled in the art to inventive concept of the present invention, technical scheme.
The present invention, by Bluetooth wireless technology, realizes the peerings of portable equipment (mobile phone etc.) and car-mounted terminal, so that the running status of Real-Time Monitoring and control vehicle.Whole system realizes the interconnected of car machine and smart mobile phone by mobile phone MHL with the audio video transmission of screen mirror image.
Mobile phone terminal mainly comprises HMI human-computer interaction module and bluetooth communication module, HMI (Human Machine Interface, " man-machine interface ") human-computer interaction module is used for sending request order to car-mounted terminal, or initiatively receive pushed information, with Real-Time Monitoring and the running state parameter showing vehicle.Bluetooth communication module connects and car machine wireless application transceiver module constitutes wireless communication networks in car, and user mobile phone installs special communication process software to realize the object by mobile phone interface and car machine exchange message.Car machine uses the modes such as physical button, touch-screen button or voice, controls mobile phone by wireless application transceiver module; Mobile phone receives the instruction of car machine by bluetooth communication module.
Car owner will comprise CAN-USB signal transmitting and receiving module, wireless application transceiver module and MHL module, and wireless application transceiver module specifies pin real-time tranception correlated digital signals by ECU, and at terminal parses relevant parameter.In the present invention, onboard wireless application transceiver module is that transfer of data reaches 24Mbps based on IEEE 802.15 Bluetooth wireless communication codes and standards; CAN-USB signal transmitting and receiving module is with the collection of Bluetooth protocol frame format, conversion and and receive and dispatch the CAN signal of specifying.
CAN-USB signal transmitting and receiving module mainly completes the information interaction between vehicle and mobile phone.Mobile phone, on the one hand can every operational factor of monitor vehicle as the window of man-machine interaction, and is presented to user visually with graphic model; On the other hand vehicle interior ECU parameter can be set, every attribute of operating and controlling vehicle.CAN-USB module of the present invention, as Che Ji signal centre, completes the mutual transmission of data between coupling terminal.The signal of this resume module mainly comprises CAN, K line and digital signal, is responsible for collection and the configuration of ECU data in car, and sets up data cube computation by CAN-USB module and Bluetooth of mobile phone communication module, and the radio communication realizing whole system controls.CAN-USB module major function comprises: in the specific car of (1) active push, data are to mobile phone; (2) under the request of mobile phone, return the data of specifying in car; (3) under the control of mobile phone, complete the configuration of car intrinsic parameter.
Audio, video data with screen mirror image is transferred to car machine by MHL module by the mobile devices such as mobile phone, realizes the interconnected of car machine and mobile phone.Mainly through MHL2.0 technology in transmitting with the audio, video data shielding mirror image, MHL 2.0 technology is the standard that exploitation can transmit high-definition audio and video signal on the basis of compatible Miro-USB interface, can support 720P 60 frame or 1080P 30 frame.While transfer of data, can charge to external equipment (smart mobile phone, PAD).
Monitoring function core process flow is as follows: first CAN-USB module receives specific CAN message or digital signal in car, and resolves its content, filter, encapsulates, and is sent to the mobile phone terminal of binding; Secondly mobile phone terminal initiatively receives corresponding CAN message frame information, carries out equity and resolves, filters and computing; Finally, digitized information, by graph abstraction process, shows user.In like manner, for the manipulation of vehicle ECU, first send instructions to vehicle-mounted end by mobile phone terminal, vehicle-mounted end is transmitted to CAN-USB module again, and then realizes the short-distance wireless remote control to vehicle.
The core process flow of whole system is: first user is from handset starting car machine monitoring application program, opens the bluetooth equipment that bluetooth discovery function searches surrounding; Then match with selected vehicle-mounted Bluetooth equipment, and connect; Last based on bluetooth protocol repertory, mobile phone terminal and car machine complete data interaction by wireless application transceiver module.
Mobile phone terminal HMI initiatively sends request message or directly obtains the message information pushed, by MHL technology, car machine will be radioed to screen mirror image data, the video data received is shown by display screen by car machine, car machine passes through after information processing, command information is sent to CAN-USB module, and after conversion, parsing and filtration treatment, CAN gathers the corresponding ECU message information of vehicle or configures.Such as, reminding incoming call of mobile phone, pushes information to car machine display screen, can select to answer by the touch-screen of car machine display screen or button etc., by mobile phone car machine interconnected systems, can realize GPS navigation, media play, the functions such as game.Mobile phone also can carry out data acquisition, the failure diagnosis of car machine by bluetooth communication module, to realize the partial function of car networking, thus really realize smart mobile phone and vehicle-mounted interactive cooperation.
In car of the present invention, communication network uses Bluetooth technology, and bluetooth is a kind of open short-distance wireless communication technology, and it is based on the near radio of low cost connects, and sets up one be connected especially for fixing with mobile device communication environment.But its fail safe and antijamming capability are not strong, for meeting basic safety and interference free performance demand, present invention employs the performance of the Novel tripping frequency sequence based on Advanced Encryption Standard iterative type block cipher structure.
One: safety analysis
Based on the frequency hop sequences of aes algorithm structure, its fail safe is determined by the security mechanism of aes algorithm.According to password design " obscuring " and " diffusion " principle that Shannon proposes, layout strategy based on the novel frequency hopping selection algorithm of Advanced Encryption Standard iterative type block cipher structure is the wide trail strategy proposed for difference analysis and linear analysis, algorithm adopts and substitutes/permutation network, meet " obscuring " and " diffusion " principle, there is very high fail safe.Finite field gf (2 in S-Box structure
8) inverse operation makes every being tending towards in linear approximation and difference profile table be uniformly distributed, and has good immunity to difference analysis and linear analysis.In a word, for known attack, the novel frequency hopping selection algorithm based on Advanced Encryption Standard iterative type block cipher structure has high fail safe, and the frequency hop sequences thus based on this algorithm also has good fail safe.
Two: analysis of Uniformity
For frequency-hopping system, according to card side's distribution inspection, the uniformity of frequency hop sequences can be weighed by formula (1).Chi-square value is less, and distribution more meets and is uniformly distributed.
Assuming that frequency hopping channel number k is 64, confidence alpha is 0.05, adopts respectively
As equal distribution inspection and continuity check standard.
Three: hamming correlation analysis
The hamming correlation of the frequency hop sequences that the mutual interference of frequency-hopping communication system is adopted by each system determines, can be represented by formula (2):
In formula, X, Y are frequency hop sequences, and 0≤τ≤N-1N represents the mould of (i+ τ).If X, Y are identical sequence, operation result represents the Hamming autocorrelation value of sequence, otherwise represents the cross correlation value of sequence.Hypothetical sequence length is 10000, and the number of channel is 64, calculates the auto-correlation of sequence and cross correlation value all should be less than
Present invention employs the error correction algorithm merging interweaving encoding and FEC, interweaving encoding data is arranged in before sending the capable N row of M to read by row again, when running into bursty interference, a longer burst error can be separated into random error.Some sheets of disturbing are of a size of m, and the interference chip size after interweaving encoding just becomes m/M.As long as m/M is less than the error correction scope of error control circuit, the impact of interference just can be overcome.The DM data of Bluetooth transmission are first through interweaving encoding process, can effectively overcome bursty interference in fading channel, adopt the 2/3FEC coding techniques can correcting random error afterwards and make mistakes retransmission mechanism to eliminate random error, thus reaching the object improving error correction probability, reduce channel bit error rate, improve transmission characteristic.
Above by reference to the accompanying drawings to invention has been exemplary description; obvious specific implementation of the present invention is not subject to the restrictions described above; as long as have employed the improvement of the various unsubstantialities that method of the present invention is conceived and technical scheme is carried out; or design of the present invention and technical scheme directly applied to other occasion, all within protection scope of the present invention without to improve.