BACKGROUND

1. Technical Field

This application is related to automobile radar systems and automobile restraint control systems, and, more particularly, to an integrated automobile radar and automobile restraint control system and method.

2. Discussion of Related Art

A restraint control system or restraint control unit (RCU) of an automobile controls detection of crash impact events in the host automobile and the deployment of pyrotechnic counter-measures. Typically, the RCU detects an impact by analyzing signals from remote contact-based sensors, such as accelerometers and/or door pressure transducers. Typically, the electrical interfaces between the remote sensors and the RCU is digital and is typically the industry standard Peripheral Sensor Interface 5 (PSI5) for automotive sensor applications.

The processing in the RCU is typically performed by a microprocessor or microcontroller, which is selected, i.e., sized, to enable the processing and analysis of multiple simultaneous crash events. The decision by the RCU as to the appropriate response to the detected event, e.g., airbag deployment, seatbelt pretensioning, must be made in a few milliseconds. These processing requirements define the performance requirements for the RCU microprocessor or microcontroller.

During normal driving, the microcontroller or microprocessor performs periodic diagnostics, but is not processing crash procedures or algorithms. Crash procedures are activated upon events by monitoring signal amplitude of specific remote sensors or specific criteria requiring little processing load. As a result, most processing resources in the RCU are unused during normal driving.

Automobile radar systems monitor the host vehicle surroundings and provide safety and/or assistance features such as blind spot detection, forward collision warning, parking assistance, etc. Current automobile radar systems are typically standalone systems or are implemented in master-slave configurations. A radar return signal is captured by a receiver antenna and down-converted by a mixer to baseband typically below 20 kHz before being digitalized by an analog-to-digital converter (ADC). Typically, the useful bandwidth of baseband signal of a homodyne receiver, which is set by the Doppler/velocity of the relevant obstacle or target, is 0-20kHz for a 24GHz radar system and 120 kHz for a 77GHz system. Typically, the radar waveform consists of 128-1024 complex points sampled with 8-16 bits resolution. The digital signal is processed by radar signal processing procedures or algorithms providing the localization (range, relative velocity, and bearing) of potential relevant obstacles. An application layer, also referred to as a feature algorithm or procedure, assesses the list of reported obstacles and makes the final decision as to an appropriate action to be taken, e.g., warning, desired speed, etc.

SUMMARY

The present inventive concept is directed to an integrated automobile restraint control and automobile radar system and method, which take advantage of the unused processing resources of the microprocessor or microcontroller of the RCU during normal driving for purposes other than crash sensing. Specifically, the processing resources of the RCU during normal driving are allocated to radar signal processing and the associated safety and/or driver comfort features such as blind spot detection, forward collision warning, and/or parking assistance. As a result, the overall cost and complexity is substantially reduced, in comparison with the conventional standalone and independent RCU and radar systems.

According to one aspect, a restraint control and radar system for an automobile is provided. The system includes at least one crash sensor for detecting a crash event and generating a signal indicative of the crash event. At least one radar receiver detects radar signals in a region near the automobile and generates at least one electrical signal indicative of the radar signals. A processor receives the at least one electrical signal from the at least one radar receiver and performs radar signal processing on the at least one electrical signal to provide radar monitoring of the region near the automobile. The processor also receives the signal indicative of the crash event and suspends the radar signal processing upon receipt of the signal indicative of the crash event to process the signal indicative of the crash event.

In some exemplary embodiments, the at least one crash sensor comprises an accelerometer. In some exemplary embodiments, the signal indicative of the crash event is indicative of severity of the crash event.

In some exemplary embodiments, the processor reallocates its processing resources in order to process the signal indicative of the crash event, upon receipt of the signal indicative of the crash event.

In some exemplary embodiments, the system further comprises an interface between the at least one radar receiver and the processor, the at least one radar receiver forwarding the at least one electrical signal to the processor over the interface.

In some exemplary embodiments, the interface is a digital interface. In some exemplary embodiments, the interface is a Peripheral Sensor Interface 5 (PSI5) interface. In some exemplary embodiments, the interface is a high-speed controller area network (CAN) interface.

In some exemplary embodiments, the radar receiver comprises at least one I/Q mixer for generating a baseband signal from the detected radar signals, the baseband signal being used in generating the at least one electrical signal.

In some exemplary embodiments, the system further comprises a data compression module for compressing data in the at least one electrical signal received by the processor.

According to another aspect, a restraint control and radar system for an automobile is provided. The system includes at least one crash sensor for detecting a crash event and generating a signal indicative of the crash event. At least one radar receiver module detects radar signals in a region near the automobile and generates at least one electrical signal indicative of the radar signals. A processor receives the at least one electrical signal from the at least one radar receiver module and performs radar signal processing on the at least one electrical signal to provide radar monitoring of the region near the automobile. The processor also receives and processes the signal indicative of the crash event. The radar receiver module comprises an interface circuit for transmitting the at least one electrical signal to the processor, the interface circuit transmitting the at least one electrical signal using a Peripheral Sensor Interface 5 (PSI5) protocol. In some exemplary embodiments, the at least one crash sensor comprises an accelerometer.

In some exemplary embodiments, the signal indicative of the crash event is indicative of severity of the crash event.

In some exemplary embodiments, the processor reallocates its processing resources in order to process the signal indicative of the crash event, upon receipt of the signal indicative of the crash event.

In some exemplary embodiments, the processor suspends the radar signal processing upon receipt of the signal indicative of the crash event in order to process the signal indicative of the crash event.

In some exemplary embodiments, the radar receiver module comprises at least one I/Q mixer for generating a baseband signal from the detected radar signals, the baseband signal being used in generating the at least one electrical signal.

In some exemplary embodiments, the radar receiver module comprises a data compression module for compressing data in the at least one electrical signal received by the processor.

According to another aspect, a restraint control and radar system for an automobile is provided. The system includes at least one crash sensor for detecting a crash event and generating a signal indicative of the crash event. At least one radar receiver module detects radar signals in a region near the automobile and generates at least one electrical signal indicative of the radar signals. A processor receives the at least one electrical signal from the at least one radar receiver module and performs radar signal processing on the at least one electrical signal to provide radar monitoring of the region near the automobile. The processor also receives and processes the signal indicative of the crash event. The radar receiver module comprises an interface circuit for transmitting the at least one electrical signal to the processor, the interface circuit transmitting the at least one electrical signal using a highspeed controller area network (CAN) protocol.

In some exemplary embodiments, the at least one crash sensor comprises an accelerometer. In some exemplary embodiments, the signal indicative of the crash event is indicative of severity of the crash event.

In some exemplary embodiments, the processor reallocates its processing resources in order to process the signal indicative of the crash event, upon receipt of the signal indicative of the crash event.

In some exemplary embodiments, the processor suspends the radar signal processing upon receipt of the signal indicative of the crash event in order to process the signal indicative of the crash event.

In some exemplary embodiments, the radar receiver module comprises at least one I/Q mixer for generating a baseband signal from the detected radar signals, the baseband signal being used in generating the at least one electrical signal.

In some exemplary embodiments, the radar receiver module comprises a data compression module for compressing data in the at least one electrical signal received by the processor.

According to another aspect, a processing method for an automobile is provided. The method includes: detecting a crash event; generating a signal indicative of the crash event; detecting radar signals in a region near the automobile; generating at least one electrical signal indicative of the radar signals; receiving the at least one electrical signal from the at least one radar receiver; performing radar signal processing on the at least one electrical signal to provide radar monitoring of the region near the automobile; receiving the signal indicative of the crash event; and suspending the radar signal processing upon receipt of the signal indicative of the crash event to process the signal indicative of the crash event.

In some exemplary embodiments, generating the signal indicative of the crash event comprises generating a signal indicative of severity of the crash event.

In some exemplary embodiments, the method further comprises reallocating processing resources to process the signal indicative of the crash event, upon receipt of the signal indicative of the crash event.

In some exemplary embodiments, the method further comprises forwarding the at least one electrical signal to the processor over an interface. In some exemplary embodiments, the interface is a digital interface. In some exemplary embodiments, the interface is a Peripheral Sensor Interface 5 (PSI5) interface. In some exemplary embodiments, the interface is a high-speed controller area network (CAN) interface.

In some exemplary embodiments, the method further comprises generating a baseband signal from the detected radar signals, the baseband signal being used in generating the at least one electrical signal.

In some exemplary embodiments, the method further comprises compressing data in the at least one electrical signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and advantages will be apparent from the more particular description of preferred embodiments, as illustrated in the accompanying drawings, in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the inventive concept.

FIG. 1 includes a schematic block diagram of a system for processing automobile radar signals and automobile restraint control signals, in accordance with some exemplary embodiments.

FIG. 2 includes a schematic logical flow diagram which illustrates operation of the system of the inventive concept, as described above in detail, in accordance with some exemplary embodiments.

DETAILED DESCRIPTION

As noted above, the present inventive concept is directed to an automobile signal processing architecture which takes advantage of the unused processing resources of the microcontroller or microprocessor of a restraint control unit (RCU) during normal driving for purposes other than crash sensing. Specifically, the RCU microcontroller or microprocessor resource is allocated during normal driving to radar signal processing and the associated safety or driver comfort features, such as forward collision warning, blind spot detection or parking assistance, thus reducing the overall cost in comparison with conventional standalone and independent RCU systems and radar systems.

According to the architecture described herein in detail, the radar sensor module is depopulated of a digital signal processor (DSP). The DSP is replaced with a lower cost digital interface circuit. Instead of having the digitalized baseband radar signals processed by the DSP in the radar module, they are transmitted by the digital interface circuit over a digital interface to the RCU for processing by the microcontroller or microprocessor in the RCU. To that end, the digital interface can be, for example, a standard PSI5 digital interface or a highspeed controller area network (CAN) digital interface for low-resolution/narrow-band radar systems, or Ethernet or Flexray for high-resolution/ultra-wide-band radar systems.

According to the exemplary embodiments, the microcontroller/microprocessor and associated circuitry including memory and peripheral circuitry of the RCU host the radar signal processing procedures and algorithms, as well as any radar-related feature procedures or algorithms. During normal driving, the RCU receives the digitized baseband radar signals over the digital interface from the radar module, and performs the appropriate radar signal processing to implement radar detection/monitoring of the region surrounding the automobile. At the same time, one or more sensors used to detect crash events continue to operate and generate alerts as appropriate. If a crash event is detected, the radar signal processing being performed by the microcontroller/microprocessor in the RCU is suspended, for example, interrupted or branched away from, and the microcontroller/microprocessor processes the crash event to issue the appropriate response, e.g., deploy airbags, etc.

FIG. 1 includes a schematic block diagram of a system 10 for processing automobile radar signals and automobile restraint control signals, in accordance with some exemplary embodiments. Referring to FIG. 1, system 10 includes a radar module 12 coupled to a restraint control unit (RCU) 14. Radar module 12 processes radar transmit and receive signals which are compatible with the radar detection and monitoring system in the host automobile, for providing one or more safety and/or assist features, such as forward collision warning, blind spot detection, parking assist, and/or other features. RCU 14 processes detections from remote sensors to make determinations as to appropriate responses to detections, such as deployment of various countermeasures, such as interior and/or exterior airbags, seatbelt pretensioners, and/or other measures. Radar module 12 generates and transmits radar signals into the region adjacent to the host vehicle that is being monitored by the radar system. Generation and transmission of signals is accomplished by RF signal generator 24, radar transmit circuitry 20 and transmit antenna 16. Radar transmit circuitry 20 generally includes any circuitry required to generate the signals transmitted via transmit antenna 16, such as pulse shaping circuitry, transmit trigger circuitry, RF switch circuitry, or any other appropriate transmit circuitry used by the radar system.

Radar module 12 also receives returning radar signals at radar receive circuitry 22 via receive antenna 18. Radar receive circuitry 22 generally includes any circuitry required to process the signals received via receive antenna 18, such as pulse shaping circuitry, receive trigger circuitry, RF switch circuitry, or any other appropriate receive circuitry used by the radar system. The received signals processed by radar receive circuitry 22 is forwarded to phase shifter circuitry 26, which generates two signals having a predetermined phase difference. These two signals, referred to as an inphase (I) signal and a quadrature (Q) signal, are mixed with an RF signal from RF signal generator 24 by mixers 28 and 30, respectively. The resulting difference signals are further filtered as required by filtering circuitry 32 to generate baseband I and Q signals, labeled "I" and "Q" in FIG. 1. The baseband I and Q signals are digitized by analog-to-digital converter circuitry (ADC) 34.

In conventional automobile radar systems, these digitized I and Q baseband signals are typically processed by a digital signal processor (DSP) in the radar module. However, in accordance with some exemplary embodiments, the digitized I and Q baseband signals are forwarded to a digital interface circuit 36, which forwards them for processing over a digital interface to RCU 14 for processing.

RCU 14 is coupled to one or more external sensor systems, generally indicated by reference numerals 48, 50 and 52 in FIG. 1. In some exemplary embodiments, sensors 48, 50 and 52 can include an accelerometer, a door pressure sensor and/or other types of sensors used to monitor the status and physical environment of the host automobile. These sensors 48, 50, 52 are used by RCU 14 to determine whether crash events have occurred. That is, RCU 14 receives signals from sensors 48, 50, 52 and processes the signals to make decisions as to whether a crash event has occurred, and, if so, the appropriate response to the crash event. These signals from sensors 48, 50, 52 can be used to determine severity of a crash event. The crash event severity is used by RCU 14 processing to make the decision as to the appropriate response.

One possible appropriate response to a crash event may be deployment of airbags. To that end, RCU 14 is coupled to one or more airbag controllers 54. If an airbag is to be deployed, RCU 14 may issue a command to airbag controller(s) 54 to deploy one or more airbags, as appropriate. Similarly, for example, RCU 14 may determine that one or more seatbelt pretensioners should be activated. The RCU can issue a command to one or more seatbelt controllers 56 to active one or more seatbelt pretensioners. It will be understood that these alerts and commands associated with RCU 14 are exemplary only. Other types of alerts and commands associated with RCU 14 are possible, within the scope of the inventive concept.

According to some exemplary embodiments, all of the communication between radar module 12 and RCU 14; between sensors 48, 50, 52 and RCU 14; and between airbag and seatbelt controllers 54, 56 and RCU 14 are carried out over a digital interface. To that end, radar module 12 includes digital interface circuit 36, and RCU 14 includes a digital interface circuit 46. Digital interface circuit 36 of radar module 12 communicates with digital interface circuit 46 of RCU 14 to forward the digitized baseband I and Q signals to RCU 14 for radar signal processing. Similarly, in some exemplary embodiments, sensors 48, 50, 52 communicate their signals to RCU 14 via digital interface circuit 46, and RCU 14 communicates its command signals to airbag and seatbelt controllers 54, 56 via digital interface circuit 46.

As described above, in some exemplary embodiments, the digital interface implemented by digital interface circuits 36 and 46 can be, for example, a standard Peripheral Sensor Interface 5 (PSI5) interface. In some exemplary embodiments, the interface can be a high-speed controller area network (CAN) interface. In some exemplary embodiments, the interface can be an Ethernet or Flexray interface.

According to some exemplary embodiments, two VQ radar receivers are used, since two I/Q radar receivers are adequate for measurement of bearing angle using a phase monopulse technique. As a result, 128 complex points with 10-bit resolution waveform of the I and Q outputs of two receivers/mixers can be transmitted in approximately 40ms via a basic point-to-point PSI5 (125kb/s) interface without compression. However, according to some exemplary embodiments data compression can be used to compress the digitized baseband I and Q signal data transferred over the interface from radar module 12 to RCU 14, in order to improve throughput.

According to the exemplary embodiments, RCU 14 processes the normal radar signals used to implement the radar monitoring and detection of the host automobile, as well as the crash event sensor signals and response commands. To that end, RCU 14 includes a processing circuit 38, which can be a microprocessor or a microcontroller, one or more memory circuits 40 as needed to store data and commands used to implement system functions, and any associated or peripheral circuitry 42 used by the processing circuit 38 and memory 40. All of the circuitry of RCU 14, including processing circuit 38, memory 40, peripheral circuitry 42 and interface circuitry 46, can be connected to and communicate via a communication bus 44.

During normal driving conditions, RCU 14 processes the digitized baseband I and Q signals received from radar module 12 over the digital interface. The I and Q signals are processed to provide radar monitoring and detection in the region adjacent to the host automobile. When one of sensors 48, 50, 52 reports a crash event, the radar signal processing being carried out by RCU 14 is suspended, e.g., interrupted or branched away from, and crash event processing of the received crash event signals is carried out. If a responsive action must be taken, RCU 14 can issue one or more commands via the interface to the appropriate controller, e.g., one or more of controllers 54, 56, to initiate the response. When processing of the crash event is completed, RCU 14 returns to radar signal processing under normal driving conditions.

FIG. 2 includes a schematic logical flow diagram which illustrates operation of the system of the inventive concept, as described above in detail, in accordance with some exemplary embodiments. All of the foregoing detailed description with regard to the system of the inventive concept is applicable to the method depicted in FIG. 2. That is, the method of FIG. 2 can be considered to be carried out by or in connection with the system and any of its features illustrated and described in detail in connection with FIG. 2.

Referring to FIG. 2, according to method 200, RCU 14 performs radar signal processing using the digitized baseband I and Q signals received from radar module 12 in step 210 under normal driving conditions. Periodically, such as when processing of one set of signals is complete, or after a preset timeout period, RCU 14 checks to determine whether a crash event has been reported, in step 220. If not, then flow returns to step 210, and radar signal processing continues. If in step 220 it is determined that a crash event has been indicated, then radar signal processing 210 is temporarily stopped, and flow proceeds to crash event processing in step 230. If in step 240 it is determined that crash event processing is complete, then flow returns to step 210 where radar signal processing resumes under normal driving conditions. If in step 240 it is determined that crash event processing is not complete, then crash event processing continues in step 230 until it is complete.

It should be noted that in FIG. 2, radar signal processing is illustrated and described as being branched away from by a conditional branch in order to carry out crash event processing. It will be understood that an interrupt service routine can also be used to suspend radar signal processing while crash even processing is carried out.

While the present inventive concept has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present inventive concept as defined by the following claims.