Patent Application
20160207495
More and more automobiles are being equipped with pedestrian protection systems. Such systems seek to reduce the risk of injury to pedestrians hit by vehicles. Regulatory bodies and performance assessment organizations consider the risk of injury to pedestrians during impacts when evaluating vehicles. Moreover, both regulatory bodies and performance assessment organizations consider reducing pedestrian injuries a top priority.
When an impact with a pedestrian cannot be avoided, a host vehicle may include a system that detects the impact with the pedestrian and initiates a countermeasure to attempt to reduce the risk of injuring the pedestrian. The system may include a sensor configured to output an impact signal and a processing device programmed to calculate an acceleration envelope from the impact signal. The processing device may be further programmed to calculate a velocity envelope from the acceleration envelope, determine a threshold value based at least in part on the vehicle speed and velocity envelope, and compare the acceleration envelope to the threshold value. The processing device may output a control signal to deploy a pedestrian protection countermeasure if the acceleration envelope exceeds the threshold value.
The elements shown may take many different forms and include multiple and/or alternate components and facilities. The example components illustrated are not intended to be limiting. Indeed, additional or alternative components and/or implementations may be used.
As illustrated in
Although illustrated as a sedan, the host vehicle 100 may include any passenger or commercial automobile such as a car, a truck, a sport utility vehicle, a crossover vehicle, a van, a minivan, a taxi, a bus, etc. In some possible approaches, the host vehicle 100 is an autonomous vehicle configured to operate in an autonomous (e.g., driverless) mode, a partially autonomous mode, and/or a non-autonomous mode.
Referring now to
AAE=max{abs(S1), abs(S2)} (1)
where S1 and S2 represent the first impact signal and the second impact signal, respectively.
The processing device 130 may be further programmed to calculate a velocity envelope from the acceleration envelope. Specifically, the velocity envelope may be based at least in part on an integral of the first and second impact signals. For instance, the velocity envelope, AVE, may be defined as:
AVE=max{abs(∫(S1)dt),abs(∫(S2)dt)} (2)
Alternatively, the velocity envelope may be defined as presented in Equation 3, below.
AVE=abs(∫(S1)dt)+abs(∫(S2)dt) (3)
With the velocity envelope, the processing may be programmed to set a pedestrian related impact threshold value. As shown in Equation 4, below, the pedestrian related impact threshold value, PRIT, may be based at least in part on the velocity envelope and host vehicle speed.
PRIT
speed
=f
speed(AVE) (4)
The pedestrian relate impact threshold value may be based at least in part on impact profiles of pedestrian related impacts. Examples of impact profiles of pedestrian related impacts are shown in
To detect a pedestrian-related impact, the processing device 130 may be programmed to compare the acceleration envelope to the pedestrian related impact threshold value based on the host vehicle speed.
At block 605, the detection system 110 may set a wakeup threshold. The wakeup threshold may be set by the processing device 130 or during calibration of the detection system 110, and may be set to a value to prevent noise output by the first sensor 120 or second sensor 125 from inadvertently triggering the pedestrian protection system 105 or other countermeasures.
At block 610, the detection system 110 may set a system exit threshold. The system exit threshold may be set by the processing device 130 or during calibration of the detection system 110. The system exit threshold may be based on the signals output by the first sensor 120 and second sensor 125 that are to be acquired or monitored following a potential impact with a pedestrian.
At block 615, the detection system 110 may set a non-pedestrian related impact threshold (NPRIT). The non-pedestrian related impact threshold may be based on the expected values for the impact signals during an impact that does not involve a pedestrian or a relatively small unknown object. For example, the non-pedestrian related impact threshold may be based on expected impact signal values for an impact involving another vehicle or a larger or heavier object. The processing device 130 may set the non-pedestrian related impact threshold. Alternatively, the non-pedestrian related impact threshold may be set during calibration. The system non-pedestrian related impact threshold may be based on the signals output by the first sensor 120 and second sensor 125 acquired or monitored following a potential impact with a non-pedestrian related object.
At block 620, the detection system 110 may set a dwell time window. The dwell time window may be set to a preselected value to monitor and control the time by which the signals output by the first sensor 120 and second sensor 125 may dwell below the exit threshold value.
At block 625, the processing device 130 may receive the impact signal. As discussed above, the impact signal may represent the impact of the host vehicle 100 with an unknown object. In some instances, such as where two sensors are mounted to the bumper 115, the processing device 130 may receive the first impact signal output by the first sensor 120 and the second impact signal output by the second sensor 125.
At decision block 630, the processing device 130 may determine whether the impact signals received at block 625 exceed the system wakeup threshold. Impact signals with magnitudes below the system wakeup threshold may be discarded as noise. If the magnitude of the impact signal exceeds the system wakeup threshold, the process 600 may continue at block 635. Otherwise, the process 600 may proceed to block 625.
At block 635, the detection system 110 may begin to process the impact signals. For example, the processing device 130 may calculate the acceleration envelope from the first and second impact signals received from the first and second sensors 120, 125, respectively. The acceleration envelope may be calculated in accordance with, e.g., Equation (1), above.
At block 640, the detection system 110 may continue to process the first and second impact signals. That is, the processing device 130 may calculate the velocity envelope. As presented above with respect to Equations (2) and (3
At block 645, the detection system 110 may obtain vehicle speed information from vehicle CAN (Controller Area Network). The processing device 130 may use the vehicle speed information to set the pedestrian related impact threshold (PRIT) in real time as shown in
At block 650, the detection system 110 may set pedestrian related impact threshold value in real time. As discussed above, the pedestrian related impact threshold value may be a function of the velocity envelope, as shown in Equation (4) and the vehicle speed. Thus, the processing device 130 may determine the pedestrian related impact threshold value based, at least in part, on the velocity envelope. Moreover, the threshold value may be based on the velocity of the host vehicle 100. The processing device 130 may receive a signal representing the velocity of the host vehicle 100.
At decision block 655, the detection system 110 may determine whether the impact involves an object much larger than a pedestrian. In other words, the detection system 110 may determine whether a pedestrian was likely involved in the impact. For instance, the processing device 130 may compare the impact signals received at block 625 to the non-pedestrian related impact threshold. If the impact signals exceed the non-pedestrian related impact threshold, the process 600 may continue at block 660. If the impact signals do not exceed the non-pedestrian related impact threshold, meaning the impact may involve a pedestrian, the process 600 may proceed to block 665.
At block 660, the detection system 110 may output a signal to initiate a non-pedestrian related front impact protection system. The signal may be output by the processing device 130. The process 600 may end after block 660.
At decision block 665, the detection system 110 may determine whether the acceleration envelope exceeds the real time threshold value PRIT set at block 650. That is, the processing device 130 may compare the acceleration envelope to the threshold value PRIT. If the acceleration envelope exceeds the threshold value PRIT, the process 600 may continue to block 670. If the acceleration envelope does not exceed the threshold value, the process 600 may continue to block 675.
At block 670, the detection system 110 may deploy a pedestrian protection countermeasure. One way to deploy the pedestrian protection countermeasure may include the processing device 130 outputting a control signal to the pedestrian protection system 105. Upon receiving the control signal, the pedestrian protection system 105 may initiate one or more pedestrian protection countermeasures. The process 500 may end after the control signal is output, the pedestrian protection countermeasures have been deployed, or both.
At decision block 675, the detection system 110 may initiate a process to determine whether the impact is over. In one possible approach, the processing device 130 may compare the outputs of the first and second sensors 120, 125 or manipulated sensor outputs, to the system exit threshold. For impact signals with magnitudes below the system exit threshold, the process 600 may proceed to block 680. For impact signals with magnitudes exceeding the system exit threshold, the process 600 may proceed to block 635.
At block 680, the detection system 110 may track how much time the outputs of the first sensor 120 and second sensor 125 dwelled below the system exit threshold The processing device 130 may initiate a count to monitor the above time by which the sensors signal output is below the exit threshold value set as in block 610.
At block 685, the detection system 110 may determine whether the amount of time that has elapsed since the signals from the first and second sensors 120 and 125 stayed below the exit threshold as determined by the block 680 exceeds the dwell time window as set in block 620. If the elapsed time exceeds the dwell time window, the process 600 may proceed to block 690. Otherwise, the process 600 may proceed to block 635.
At block 690, the processing device 130 may reset the elapsed time counter to zero, and the process 600 may proceed to block 625.
The process 600 may continue to execute until the host vehicle 100 is turned off or until after blocks 660 or 670 have been executed.
In general, the computing systems and/or devices described may employ any of a number of computer operating systems, including, but by no means limited to, versions and/or varieties of the Ford Sync® operating system, the Microsoft Windows® operating system, the Unix operating system (e.g., the Solaris® operating system distributed by Oracle Corporation of Redwood Shores, Calif.), the AIX UNIX operating system distributed by International Business Machines of Armonk, N.Y., the Linux operating system, the Mac OSX and iOS operating systems distributed by Apple Inc. of Cupertino, Calif., the BlackBerry OS distributed by Blackberry, Ltd. of Waterloo, Canada, and the Android operating system developed by Google, Inc. and the Open Handset Alliance. Examples of computing devices include, without limitation, an on-board vehicle computer, a computer workstation, a server, a desktop, notebook, laptop, or handheld computer, or some other computing system and/or device.
Computing devices generally include computer-executable instructions, where the instructions may be executable by one or more computing devices such as those listed above. Computer-executable instructions may be compiled or interpreted from computer programs created using a variety of programming languages and/or technologies, including, without limitation, and either alone or in combination, Java™, C, C++, Visual Basic, Java Script, Perl, etc. In general, a processor (e.g., a microprocessor) receives instructions, e.g., from a memory, a computer-readable medium, etc., and executes these instructions, thereby performing one or more processes, including one or more of the processes described herein. Such instructions and other data may be stored and transmitted using a variety of computer-readable media.
A computer-readable medium (also referred to as a processor-readable medium) includes any non-transitory (e.g., tangible) medium that participates in providing data (e.g., instructions) that may be read by a computer (e.g., by a processor of a computer). Such a medium may take many forms, including, but not limited to, non-volatile media and volatile media. Non-volatile media may include, for example, optical or magnetic disks and other persistent memory. Volatile media may include, for example, dynamic random access memory (DRAM), which typically constitutes a main memory. Such instructions may be transmitted by one or more transmission media, including coaxial cables, copper wire and fiber optics, including the wires that comprise a system bus coupled to a processor of a computer. Common forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, any other magnetic medium, a CD-ROM, DVD, any other optical medium, punch cards, paper tape, any other physical medium with patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EEPROM, any other memory chip or cartridge, or any other medium from which a computer can read.
Databases, data repositories or other data stores described herein may include various kinds of mechanisms for storing, accessing, and retrieving various kinds of data, including a hierarchical database, a set of files in a file system, an application database in a proprietary format, a relational database management system (RDBMS), etc. Each such data store is generally included within a computing device employing a computer operating system such as one of those mentioned above, and are accessed via a network in any one or more of a variety of manners. A file system may be accessible from a computer operating system, and may include files stored in various formats. An RDBMS generally employs the Structured Query Language (SQL) in addition to a language for creating, storing, editing, and executing stored procedures, such as the PL/SQL language mentioned above.
In some examples, system elements may be implemented as computer-readable instructions (e.g., software) on one or more computing devices (e.g., servers, personal computers, etc.), stored on computer readable media associated therewith (e.g., disks, memories, etc.). A computer program product may comprise such instructions stored on computer readable media for carrying out the functions described herein.
With regard to the processes, systems, methods, heuristics, etc. described herein, it should be understood that, although the steps of such processes, etc. have been described as occurring according to a certain ordered sequence, such processes could be practiced with the described steps performed in an order other than the order described herein. It further should be understood that certain steps could be performed simultaneously, that other steps could be added, or that certain steps described herein could be omitted. In other words, the descriptions of processes herein are provided for the purpose of illustrating certain embodiments, and should in no way be construed so as to limit the claims.
Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments and applications other than the examples provided would be apparent upon reading the above description. The scope should be determined, not with reference to the above description, but should instead be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. It is anticipated and intended that future developments will occur in the technologies discussed herein, and that the disclosed systems and methods will be incorporated into such future embodiments. In sum, it should be understood that the application is capable of modification and variation.
All terms used in the claims are intended to be given their ordinary meanings as understood by those knowledgeable in the technologies described herein unless an explicit indication to the contrary is made herein. In particular, use of the singular articles such as “a,” “the,” “said,” etc. should be read to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.
The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.
