Enhanced discrimination method and apparatus for controlling an actuatable protective device - Patents.com

Abstract

To provide an enhanced discriminant method and apparatus for classifying several particular types of vehicle crash events.SOLUTION: A controller is configured to execute discrimination algorithm comprising at least one classification metric that utilizes at least one of vehicle pitch rate (P_RATE) and vehicle roll acceleration (D_RATE) to discriminate at least one of a ramp rollover event and a soil rollover event from an embankment rollover event. The discrimination algorithm determines a classification of the vehicle rollover event as one of the ramp rollover event, the soil rollover event, and the embankment rollover event. The controller is also configured to select a deployment threshold for deploying an actuatable restraint. The deployment threshold corresponds to the classification of the vehicle rollover event.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to methods and apparatus for controlling actuatable occupant protection devices in a vehicle, and more particularly to an enhanced discrimination method and apparatus for classifying certain specific types of vehicle crash events. [Background technology]

[0002]

[0002] A vehicle safety system includes a central control unit ("CCU") that utilizes sensors both local to the CCU and remote from the CCU to detect the occurrence of crash events involving the vehicle and determine whether these events merit activation of actuatable restraint devices such as airbags and seat belt retractors. The sensors utilized by the CCU can include accelerometers and other sensors such as impact sensors, seat belt buckle switches, seat pressure switches, steering angle sensors, etc. Using data from these sensors, the CCU can determine the occurrence of a vehicle crash event and can implement discrimination algorithms to classify the crash event as one of a particular type. The CCU can activate actuatable restraint devices due to a particular type of crash event.

[0003]

[0003] It is desirable for a vehicle safety system to distinguish between various crash events in which a vehicle may be involved. "Discriminating" a crash event can mean classifying the crash event as a certain type of crash event and distinguishing the crash event from other types of crash events. If the vehicle safety system can distinguish or identify the crash event as a certain type, the actuatable restraint device can be activated in a manner appropriate for the certain type of crash event. "Crash event" as used herein can be used to encompass various events involving a vehicle. For example, crash events can be collisions or impacts in which the vehicle strikes, impacts, or becomes involved with different types of structures. These crash events can be collisions with deformable obstacles, such as another vehicle, or collisions with non-deformable obstacles, such as a tree or utility pole. As another example, crash events can further include events such as rollover events in which the impact of the vehicle results in the vehicle rolling over. A rollover event may occur by a vehicle skidding sideways and striking a curb, by sliding or moving down an embankment from the side of the road, or by sliding or moving up a slope such as a hill from the side of the road.

[0004]

[0004] Vehicle safety systems may be configured or adapted to distinguish between events in which deployment of an actuatable restraint is desired (a "deployment event") and events in which deployment of an actuatable restraint is not desired (a "non-deployment event"). Crash discrimination involves determining the type of event, for example, deformable obstacle, non-deformable obstacle, front impact crash, rear impact crash, side impact crash, oblique crash, offset crash, rollover, etc. Crash discrimination further involves determining the severity of the crash and implementing safety features that act as checks or tolerances to ensure that the actuatable restraint is deployed in a safe manner.

[0005]

[0005] From the above, it will be appreciated that it may be desirable to control the activation and timing of actuatable restraint devices in a safety system depending on the type and / or severity of a crash event in which a vehicle is involved. To determine which occupant protection devices to activate in response to a detected crash event, the safety system may perform a crash evaluation process to determine the type of crash event. If the identified crash event meets or exceeds a severity threshold, and safing functions agree, actuatable restraint devices may be activated in a manner commensurate with the determined event type.

[0006]

[0006] For many years, safety standards have been compiled and updated to "push the envelope" when it comes to motor vehicle safety. As a result, in maintaining the standards, motor vehicle manufacturers have been forced to constantly improve the safety of their products. As the standards have become stricter, safety systems have adapted and become more complex and capable. Throughout the evolution of vehicle safety systems, it has been discovered that crash classification is one of the key aspects that helps determine the effectiveness of the system. If a safety system can accurately and robustly identify crash scenarios as defined by the safety standards, it can take tailored measures to provide the best outcome for occupants involved in the accidents for which the standards are designed.

[0007]

[0007] While vehicle safety systems have been developed with the ability to discriminate between various crash events, there is a continuing need to further classify and discriminate between crash events so that the vehicle safety systems can take appropriate response actions. Among the crash events for which discrimination may be desired may be various types of side crash events, such as rollover events or events that may lead to a rollover.

[0008]

[0008] A side impact event is one in which it may be desirable to activate safety devices such as side airbags (curtain airbags, thorax airbags) and / or seatbelt pretensioners. Side impact events can occur in a variety of scenarios. For example, a vehicle may lose control and slide sideways off the road, onto adjacent grass / soil, down an embankment, or up a slope or hill. In another example, a vehicle may lose control and slide sideways toward a low obstacle such as a curb. In any of these scenarios, the magnitude of the resulting side impact event may merit activation of one or more vehicle safety devices. Summary of the Invention [Means for solving the problem]

[0009]

[0009] The vehicle safety system includes an actuatable restraint device for assisting in protecting a vehicle occupant and a controller for controlling actuation of the actuatable restraint device in response to a vehicle rollover event. The controller is configured to execute a discrimination algorithm including at least one classification metric utilizing at least one of a vehicle pitch rate (P_RATE) and a vehicle roll acceleration (D_RATE) to discriminate at least one of a bank rollover event and a pitch roll event from a bank rollover event. The discrimination algorithm determines a classification of the vehicle rollover event as one of a pitch roll event, a pitch roll event, a bank rollover event, and a rollover event. The controller is further configured to select a deployment threshold for deploying the actuatable restraint device. The deployment threshold corresponds to a classification of the vehicle rollover event.

[0010] According to one aspect, the at least one classification metric may include a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE).

[0011] According to another aspect, alone or in combination with any other aspect, the at least one classification metric can include a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE). The controller can be configured to execute the classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a bank rollover event from a bank rollover event.

[0012] According to another aspect, alone or in combination with any other aspect, the at least one classification metric can include a classification metric that evaluates vehicle pitch rate (P_RATE) versus vehicle roll angle (R_ANGLE). The controller can be configured to execute the classification metric that evaluates vehicle pitch rate (P_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a bank rollover event from a bank rollover event.

[0013] According to another aspect, alone or in combination with any other aspect, the at least one classification metric can also include a classification metric evaluating vehicle lateral acceleration moving average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE). The controller can be configured to execute the classification metric evaluating vehicle lateral acceleration moving average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE) to verify the discrimination between a bank rollover event and a bank rollover event.

[0014] According to another aspect, alone or in combination with any other aspect, the at least one classification metric can include a classification metric evaluating vehicle vertical acceleration moving average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE). The controller can be configured to execute the classification metric evaluating vehicle vertical acceleration moving average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE) to verify discrimination between a bank rollover event and a bank rollover event.

[0015] According to another aspect, alone or in combination with any other aspect, the at least one classification metric can include a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE). The controller can be configured to execute the classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a dirt rollover event from an embankment rollover event.

[0016] According to another aspect, alone or in combination with any other aspect, the discrimination algorithm can include a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2). The controller can be configured to execute the classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2) to discriminate a dirt rollover event from an embankment rollover event.

[0017]

[0017] According to another aspect, alone or in combination with any other aspect, the controller may be configured to perform a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2) to distinguish between hard soil rollover events, medium soil rollover events, and soft soil rollover events.

[0018] According to another aspect, alone or in combination with any other aspect, the at least one classification metric can include a classification metric that evaluates vehicle lateral acceleration moving average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE). The controller can be configured to execute the classification metric that evaluates vehicle lateral acceleration moving average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE) to distinguish a dirt rollover event from a bank rollover event.

[0019] According to another aspect, alone or in combination with any other aspect, the at least one classification metric can include a classification metric that evaluates vehicle vertical acceleration moving average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE). The controller can be configured to execute the classification metric that evaluates vehicle vertical acceleration moving average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE) to verify the distinction between a dirt rollover event and an embankment rollover event.

[0020] According to another aspect, alone or in combination with any other aspect, the controller may be configured to execute a deployment threshold metric to determine whether to activate an actuatable restraint device. The deployment threshold metric evaluates vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE), and the controller is configured to deploy the actuatable restraint device in response to the deployment threshold metric exceeding a deployment threshold.

[0021] According to another aspect, alone or in combination with any other aspect, the system may further include an accelerometer for sensing vehicle lateral acceleration and providing a signal indicative of the sensed vehicle lateral acceleration (CCU_1Y). The system may further include an accelerometer for sensing vehicle vertical acceleration and providing a signal indicative of the sensed vehicle vertical acceleration (CCU_6Z). The system may further include a roll rate sensor for sensing a vehicle roll rate value and providing a signal indicative of the sensed vehicle roll rate value (CCU_4R).

[0022] According to another aspect, alone or in combination with any other aspect, the controller: determining a vehicle lateral acceleration running average (CCU_1Y_AMA) from a signal indicative of a sensed vehicle lateral acceleration (CCU_1Y); determining a vehicle vertical acceleration running average (CCU_6Z_AMA) from a signal indicative of a sensed vehicle vertical acceleration (CCU_6Z); determining a vehicle roll acceleration (D_RATE) from a signal indicative of a sensed vehicle roll rate value (CCU_4R); determining a vehicle roll angle (R_ANGLE) from a signal indicative of a sensed vehicle roll rate value (CCU_4R); The vehicle is configured to perform vehicle metric calculations to:

[0023] According to another aspect, alone or in combination with any other aspect, the system may further include a pitch rate sensor for sensing a vehicle pitch rate value and providing a signal (CCU_5P) indicative of a sensed vehicle pitch rate. The controller may be configured to perform a vehicle metric calculation to determine a vehicle pitch rate (P_RATE) from the signal (CCU_5P) indicative of the sensed vehicle pitch rate.

[0024]

[0024] According to another aspect, alone or in combination with any other aspect, the actuable restraint device may include at least one of a seat belt anchor pretensioner, a seat belt retractor pretensioner, a curtain airbag, a thorax airbag, a side airbag, an emergency notification, a door unlock command, and a high voltage powertrain cut off command.

[0025]

[0025] According to another aspect, alone or in combination with any other aspect, the controller may be configured to issue at least one of an emergency notification, a door unlock command, and a high voltage powertrain shut-off command in response to actuating an operable restraint device.

[0026] The foregoing and other features and advantages of the present invention will become apparent to those skilled in the art from a consideration of the following description of the invention and the accompanying drawings. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a block diagram illustrating a vehicle safety system. [Diagram 2]

[0028] FIG. 2 is a block diagram illustrating metric calculations implemented in a vehicle safety system. [Diagram 3]

[0029] FIG. 13 is a diagram of a deployment threshold metric for determining the occurrence of vehicle roll for various surface conditions. [Figure 4]

[0030] FIG. 2 is a schematic block diagram illustrating a slope discrimination algorithm implemented by the vehicle safety system. [Diagram 5]

[0031] FIG. 1 is a schematic block diagram illustrating an embankment discrimination algorithm implemented by the vehicle safety system. [Figure 6]

[0032] FIG. 2 is a schematic block diagram illustrating a hard soil discrimination algorithm implemented by the vehicle safety system. [Figure 7]

[0033] FIG. 1 is a schematic block diagram illustrating a neutral soil discrimination algorithm implemented by the vehicle safety system. [Figure 8]

[0034] FIG. 2 is a schematic block diagram illustrating a soft soil discrimination algorithm implemented by the vehicle safety system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028]

[0035] The present invention relates to a vehicle safety system that implements an enhanced discrimination algorithm that can discriminate and classify between a bank rollover crash event and a slope rollover crash event. The enhanced discrimination algorithm implemented by the vehicle safety system can also discriminate and classify a bank event from a trip event. The enhanced discrimination algorithm implemented by the vehicle safety system can further discriminate and classify hard soil, medium soil, and soft soil trip events.

[0029]

[0036] Because the present invention is directed to enhanced discrimination of the events mentioned in the previous paragraph, the vehicle safety system is shown and described herein as including the necessary components and implementing the algorithms to perform these particular enhanced discrimination functions. Those skilled in the art will appreciate that the vehicle safety system can include components in addition to those shown and described herein, and can implement discrimination algorithms in addition to those shown and described herein.

[0030]

[0037] 1, according to one exemplary configuration, a vehicle safety system 10 includes a central control unit (CCU) 50 that functions to activate one or more actuatable restraint devices 20, such as left / right seat belt pretensioners (anchors and / or retractors), left / right curtain airbags, left / right thorax airbags, and left / right side airbags. The CCU 50 further functions to control the activation of other protective devices, such as frontal and knee airbags.

[0031]

[0038] The CCU 50 may also function to control other vehicle safety features 22, such as emergency notifications, automatic door release commands, and electric vehicle (EV) high voltage power cut-off commands. For example, emergency notifications may include emergency response (fire / EMS) notifications or requests issued via vehicle-based emergency assistance systems, such as GM Onstar®, Ford SYNC®, and Chrysler Uconnect®. In electric vehicles, a high voltage cut-off command may disconnect the vehicle battery from the vehicle's electrical system to reduce the risk of shock or fire due to an electrical short or failure.

[0032]

[0039] The CCU 50 includes one or more sensors that function to provide signals indicative of the linear and / or angular acceleration and / or velocity of the vehicle's motion in various directions and for various vehicle axes. The sensors may be mounted locally within or on the CCU 50 itself, or may be remote from the CCU and internally connected to the CCU, for example, via wiring. These vehicle axes include an X-axis that extends longitudinally of the vehicle in the forward / rearward direction of the vehicle path. A Y-axis of the vehicle extends laterally of the vehicle and is orthogonal to the X-axis. A Z-axis of the vehicle extends vertically of the vehicle and is orthogonal to both the X-axis and the Y-axis. The X, Y, and Z-axes are said to intersect at the center of gravity of the vehicle.

[0033]

[0040] The CCU 50 includes an accelerometer 52 for sensing the lateral (Y-axis) acceleration of the vehicle (CCU_1Y). The CCU 50 further includes an accelerometer 54 for sensing the vertical (Z-axis) acceleration of the vehicle (CCU_6Z). The CCU 50 further includes a pitch rate sensor 56 for sensing a vehicle pitch rate value (CCU_5P), i.e., the pitch rate about the Y-axis of the vehicle. The CCU 50 further includes a roll rate sensor 58 for sensing a vehicle roll rate value (CCU_4R), i.e., the roll rate about the X-axis of the vehicle. It may be desirable to position sensors on or near each axis along or about the axes along which the sensors sense vehicle motion. Since the sensors may be mounted locally on the CCU 50, it may be desirable to mount the CCU at or near the center of gravity of the vehicle.

[0034]

[0041] Hardware and software configurations for CCUs implemented in vehicle safety systems are known in the art. Thus, a detailed description of the hardware configuration of the CCU 50 is not necessary for those skilled in the art to understand and appreciate the vehicle safety system 10. The CCU 50 of FIG. 1 includes a central processing unit (CPU) 60, such as a microcomputer, configured to receive signals CCU_1Y, CCU_6Z, CCU_4R, and CCU_5P from their respective sensors, perform vehicle metric calculations 70 on these signals, and implement an enhanced discrimination algorithm 80 utilizing the calculated metrics.

[0035]

[0042] Vehicle metrics resulting from calculation 70 include: Vehicle lateral Y-axis acceleration moving average (CCU_1Y_AMA). Vehicle vertical Z-axis acceleration moving average (CCU_6Z_AMA). Vehicle roll differential rate, i.e. roll acceleration (D_RATE). Vehicle pitch rate (P_RATE). Vehicle roll rate (R_RATE), and vehicle roll angle (R_ANGLE).

[0036]

[0043] The enhanced discrimination algorithms 80 include a rollover discrimination algorithm 82, a slope / bank discrimination algorithms 84, 86, and hard / medium / soft soil discrimination algorithms 88, 90, 92. The CCU 50 is configured to perform the vehicle metric calculations 70 and the enhanced discrimination algorithms 80 to determine which, if any, of the operable restraint devices 20 to activate.

[0037]

[0044] 2 illustrates a vehicle metric calculation 70 performed by the CCU 50. The elements of the vehicle metric calculation 70 shown in FIG. 2 are referred to herein as "functions" that are performed internally by the CCU 50.

[0038]

[0045] Roll Rate Metrics According to the vehicle metric calculation 70, an analog-to-digital converter (ADC) function 100 converts the roll rate CCU_4R signal to a digital signal. The ADC 100 may implement, for example, a 10-bit 8-sample summation in 125 μs. In the rail / bias function 102, a rail check and bias adjustment are performed, for example, in 1 ms. The digitized and biased roll rate CCU_4R is passed to a high-pass filter (HPF) function 104, which may be selected, for example, to have a time constant, so that the filter function is reset after a predefined time, for example T=8 seconds. The high-pass filtered roll rate CCU_4R generated in the HPF function 104 is passed to a low-pass filter (LPF) function 106, which has a variable corner frequency, also known as the cutoff frequency, as determined by a rate shift function 108. For example, in the rate shift function 108, the corner / cutoff frequency is selected from the following: [Table 1]

[0039]

[0046] The LPF function 106 generates a roll rate metric R_RATE, which has a value indicative of the vehicle roll rate (i.e., angular velocity), and which is implemented in the enhanced discrimination algorithm 80 (see FIG. 1). The R_RATE is passed to an integral high pass filter (IHPF) function 110, which includes an integrator function and a dual time constant high pass filter function. The IHPF function 110 integrates the R_RATE signal to generate a value indicative of the determined vehicle relative roll angle. The IHPF function 110 further performs high pass filtering of the R_RATE signal. The IHPF function 110 generates a metric R_ANGLE, which is implemented in the enhanced discrimination algorithm 80 (see FIG. 1).

[0040]

[0047] R_ANGLE indicates a normalized roll angle of the vehicle, where R_ANGLE is a measure of the relative angular rotation of the vehicle in response to a sensed roll rate. The IHPF function 110 can reset R_ANGLE based on a time constant for the high pass filter function such that R_ANGLE provides an indication of angular rotation during the detected roll rate. Thus, R_ANGLE may not be indicative of the actual angular orientation of the vehicle relative to the ground. In this manner, the determination of a rollover condition of the vehicle need not depend on a determination of the initial angular orientation of the vehicle relative to the ground or road.

[0041]

[0048] The high pass filtered roll rate CCU_4R produced by HPF function 104 is also passed to a low pass filter (LPF) function 112, which is also a variable corner / cutoff frequency LPF as determined by rate shift function 108 (see table above). LPF function 112 produces a roll rate metric R_RATE_LPF, which has a value indicative of the vehicle roll rate (i.e., angular velocity). R_RATE_LPF is implemented in enhanced discrimination algorithm 80 (see FIG. 1). R_RATE_LPF can be thought of as a band pass filtered roll rate value, since it is the product of both high pass and low pass filtering.

[0042]

[0049] The high pass filtered roll rate CCU_4R produced by HPF function 104 is also passed to a moving average function 120 and then to a moving average function 122. Each moving average function 120, 122 may be tunable, for example to select a number of samples (e.g., between 1 and 32 samples). The moving average functions 120, 122 smooth out the fluctuations in the roll rate and generate a metric R_RATE_2 that is implemented in the enhanced discrimination algorithm 80 (see FIG. 1).

[0043]

[0050] R_RATE_2 is applied to a difference function 124 where the difference between the current sample and the previous sample is compared. This produces a differentiated roll rate metric D_RATE, where D_RATE indicates the rate of change or acceleration of the roll rate. This roll acceleration D_RATE is the angular acceleration of the vehicle about the vehicle's X-axis. The roll acceleration D_RATE is implemented in an enhanced discrimination algorithm 80 (see FIG. 1).

[0044]

[0051] Pitch Rate Metrics According to the vehicle metric calculation 70, an analog-to-digital converter (ADC) function 130 converts the pitch rate CCU_5P signal to a digital signal. The ADC 130 may implement, for example, a 10-bit 8-sample summation in 125 μs. In the rail / bias function 132, a rail check and bias adjustment are performed, for example, in 1 ms. The digitized and biased pitch rate CCU_5P is passed to a high-pass filter (HPF) function 134, which may be selected, for example, to have a time constant, so that the filter function is reset after a predefined time, for example T=8 seconds. The high-pass filtered pitch rate CCU_5PR generated by the HPF function 134 is passed to a low-pass filter (LPF) function 136. The LPF function 136 generates a pitch rate metric P_RATE, which has a value indicative of the vehicle pitch rate (i.e., angular velocity), which is implemented in the enhanced discrimination algorithm 80 (see FIG. 1).

[0045]

[0052] Lateral Acceleration Metrics According to the vehicle metric calculation 70, an analog-to-digital converter (ADC) function 140 converts the lateral (Y-axis) acceleration CCU_1Y signal. The ADC 140 may implement, for example, a 10-bit 8-sample summation in 125 μs. In a rail / bias function 142, a rail check and bias adjustment are performed, for example, in 1 ms. The digitized and biased lateral acceleration CCU_1Y is passed to a high-pass filter (HPF) function 144, which may be selected, for example, to have a time constant, so that the filter function is reset after a predefined time, for example T=8 seconds. The high-pass filtered lateral acceleration CCU_1Y generated by the HPF function 144 is passed to a low-pass filter (LPF) function 146. The low-pass filtered lateral acceleration CCU_1Y value generated by the LPF function 146 is passed to moving average blocks 148 and 150, which generate the lateral acceleration metrics CCU_1Y_AMA and CCU_1Y_AMA_SAFE, respectively. The number of samples included in each of the moving average functions 148, 150 can be fine-tuned within a predetermined range, such as from 1 to 32 samples. CCU_1Y_AMA and CCU_1Y_AMA_SAFE are the lateral acceleration moving average values ​​implemented in the enhanced discrimination algorithm 80 (see FIG. 1).

[0046]

[0053] Vertical Acceleration Metrics According to the vehicle metric calculation 70, an analog-to-digital converter (ADC) function 160 converts the vertical (Z-axis) acceleration CCU_6Z signal. The ADC 140 may implement, for example, a 10-bit 8-sample summation in 125 μs. In the rail / bias function 162, a rail check and bias adjustment are performed, for example, in 1 ms. The digitized and biased vertical acceleration CCU_6Z is passed to a high-pass filter (HPF) function 164, which may be selected, for example, to have a time constant, so that the filter function is reset after a predefined time, for example T=8 seconds. The high-pass filtered lateral acceleration CCU_6Z generated by the HPF function 164 is passed to a low-pass filter (LPF) function 166. The low-pass filtered lateral acceleration CCU_6Z value generated by the LPF function 166 is passed to moving average blocks 168 and 170, which generate the lateral acceleration metrics CCU_6Z_AMA and CCU_6Z_AMA_SAFE, respectively. The number of samples included in each of the moving average functions 168, 170 can be fine-tuned within a predetermined range, such as from 1 to 32 samples. CCU_6Z_AMA and CCU_6Z_AMA_SAFE are the lateral acceleration moving average values ​​implemented in the enhanced discrimination algorithm 80 (see FIG. 1).

[0047]

[0054] Roll Threshold The ability to distinguish between various types of rollover events allows for adjustment of the thresholds that trigger deployment of the actuatable restraint device 20 (see FIG. 1). These thresholds are illustrated in FIG. 3, which illustrates deployment threshold metrics for actuating the actuatable restraint device based on thresholds for various rollover event classifications. As shown in FIG. 3, the deployment threshold metrics are based on a comparison of R_RATE and R_ANGLE. The threshold determinations in FIG. 3 illustrate left roll (i.e., roll toward the driver's side) as indicated by R_RATE and R_ANGLE values ​​in one direction (e.g., positive), and right roll (i.e., roll toward the passenger side) as indicated by values ​​for R_RATE and R_ANGLE in the opposite direction (e.g., negative).

[0048]

[0055] As shown in Figure 3, the soft soil rollover event classification has the lowest threshold for triggering deployment of the actuatable restraints. Medium soil conditions have the next lowest rollover event classification threshold for triggering deployment of the actuatable restraints, followed by hard soil, slope, and then fill. Normal conditions, i.e., conditions not classified with any other threshold, have the highest deployment trigger threshold. These deployment threshold triggers may be latched, in which case the latch can be reset if the metric falls into the reset window shown in Figure 3.

[0049]

[0056] Also, as shown, the trigger thresholds may require some threshold R_ANGLE to be detected as shown by the vertical lines, i.e., to the left of the left roll threshold and to the right of the right roll threshold. Once the required R_ANGLE is satisfied, the thresholds become substantially flat, meaning that the roll rate (R_RATE) is highly determinative of which, if any, of the thresholds are satisfied.

[0050]

[0057] Improved discrimination algorithm According to the present invention, the enhanced discrimination algorithm utilizes the vehicle metrics determined in FIG. 2 to discriminate and classify a vehicle rollover event to determine whether to activate an actuatable restraint device using the correct rollover threshold (FIG. 3). A rollover event can be classified as a pitch, bank, or soil (hard, medium, soft) event. By "discriminate," it is meant that the classification of a vehicle rollover event not only identifies the type of rollover event that has occurred, but also that the event is not one of the other events that the algorithm is configured to discriminate. Thus, for example, if the enhanced discrimination algorithm is configured to discriminate between a pitch and a bank rollover event, classifying an event as a pitch rollover event also means that the event is not a bank rollover event.

[0051]

[0058] A tilt event is an event where the vehicle engages an inclined surface resulting in vehicle roll / rollover. An embankment event is an event where the vehicle engages an inclined surface resulting in vehicle roll / rollover. A soil event is an event where the vehicle travels laterally over soil resulting in vehicle roll / rollover. Soil events can be hard, medium, or soft. Soft soil is just a soft ground such as normal grass / turf that offers low resistance to further lateral movement of the vehicle. Hard soil is classified as hard packed soil, gravel, rocks, curbs, or other road level obstacles that cause the vehicle to "trip" and the tire / wheel road contact area becomes trapped or stopped with high resistance to further lateral movement of the vehicle. Medium soil is classified as offering a degree between hard and soft soil events or resistance to lateral vehicle movement.

[0052]

[0059] In discriminating between various vehicle rollover events, it may be difficult to separate a pitch event (e.g., left pitch and right bank) from a bank event (e.g., left pitch and right bank) because they exhibit similar characteristics. It may also be difficult to separate a land event from a bank event because they also develop in the same way. In other words, a bank is easily confused with a pitch event and a land event. The enhanced discrimination algorithm 80 implemented in the vehicle safety system 10 utilizes the pitch rate P_RATE and the roll acceleration D_RATE to enhance the classification of these events. In this description, this improved classification may be referred to as improving the separation of these events. This is because the classification metric implemented in the enhanced discrimination algorithm is developed such that the values ​​of the classification metric are different enough to discriminate between the events.

[0053]

[0060] Tilt and bank rollover events develop slowly. During a tilt rollover, the vehicle moves upwards, whereas during a bank rollover event, the vehicle moves downwards. Physically, the vehicle's vertical acceleration can distinguish between a tilt and a bank. However, during a bank event, the vertical acceleration is not significant. Therefore, it can be difficult to distinguish a bank event from a tilt or a soil event using vertical acceleration as a determining factor. Advantageously, the enhanced discrimination algorithm 80 utilizes the vehicle metrics determined in FIG. 2 to enhance the classification of tilts and bank.

[0054]

[0061] The enhanced discrimination algorithm implements what is referred to as a classification metric to discriminate between various rollover events. The classification metric is a comparison of two of the vehicle metrics (see FIG. 2), i.e., Metric A versus Metric B, and may be illustrated by a graph or plot. Although shown graphically, it should be appreciated that the classification metric may be calculated by mathematical operations on the CPU 60.

[0055]

[0062] Tilt and fill events A tilt event is an event where a rollover occurs due to one side of the vehicle moving up a structure that acts as a tilt on that side of the vehicle. This can occur, for example, when one side of the vehicle is lifted by a concrete highway lane obstacle. An embankment event is an event where a rollover occurs due to one side of the vehicle moving down an embankment on the side of the road. For example, in comparison to a left vehicle rollover event, a left tilt rollover event occurs when the right side of the vehicle moves / accelerates upward along a sloped structure, causing a left roll about the vehicle's longitudinal X-axis. A left embankment rollover event occurs when the left side of the vehicle moves / accelerates downward along an embankment structure, causing a left roll about the vehicle's longitudinal X-axis. For purposes of providing enhanced occupant protection, it may be advantageous to distinguish a tilt event from an embankment event.

[0056]

[0063] Slope discrimination The tilt discrimination algorithm 84 is shown in Figure 4. The tilt discrimination algorithm 84 is used to determine whether to use a tilt threshold (see Figure 3) when deploying an actuatable restraint. The tilt discrimination algorithm 84 in Figure 4 is shown for a left roll event, i.e., the vehicle rolls to the left or driver's side. However, it should be appreciated that the algorithm shown in Figure 4 also applies to a right roll event, the only difference being the opposite sign (+ / -) of the values ​​used in the classification metric. In other words, the classification metric for a right roll event is the same as the metric shown in Figure 4 except that the signs of each axis for the different metric values ​​in the classification metric are opposite, e.g., negative instead of positive, and vice versa.

[0057]

[0064] The tilt discrimination algorithm 84 implements four different classification metrics to discriminate tilt events. The four classification metrics are: · CCU_1Y_AMA vs R_ANGLE ·CCU_6Z vs R_ANGLE D_RATE vs. R_ANGLE P_RATE vs. R_ANGLE

[0058]

[0065] The USE RAMP THRESHOLD decision is made at block 212 in response to all of the classification metrics 200, 202, 204, 206 provided to the AND block 208 being satisfied, i.e., a Boolean value of 1, herein denoted as ON. The USE RAMP THRESHOLD decision 212 may be a latched decision, as indicated by the LATCH block 210. Thus, once the AND block 208 is satisfied, the USE RAMP THRESHOLD 212 is ON and remains ON by the LATCH 210, even after the classification metrics provided to the AND block 208 have ceased to be ON. The classification metrics 200, 202, 204, 206 provided to the AND block 208 are described in the following paragraphs.

[0059]

[0066] The lateral acceleration vs. roll angle classification metric 200 utilizes CCU_1Y_AMA and R_ANGLE to generate an output that is provided to an AND block 208. As shown, the lateral acceleration vs. roll angle classification metric 200 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the lateral acceleration vs. roll angle classification metric 200 represents the metric when the vehicle is experiencing a lean roll event. The lateral acceleration vs. roll angle classification metric 200 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the lateral acceleration vs. roll angle classification metric 200 does not generate enough separation to reliably distinguish between lean events and bank events. Therefore, the lateral acceleration vs. roll angle classification metric 200 is utilized as a confirmation (at AND block 208) in the lean discrimination algorithm 84 when the other classification metrics 202, 204, 206 agree in determining the occurrence of a lean event.

[0060]

[0067] The vertical acceleration vs. roll angle classification metric 202 utilizes CCU_6Z_AMA and R_ANGLE to generate an output, which is provided to an AND block 208. As shown, the vertical acceleration vs. roll angle classification metric 202 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the vertical acceleration vs. roll angle classification metric 202 represents the metric when the vehicle is experiencing a lean roll event. The vertical acceleration vs. roll angle classification metric 202 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the vertical acceleration vs. roll angle classification metric 202 does not generate enough separation to reliably distinguish between lean events and bank events. Therefore, the vertical acceleration vs. roll angle classification metric 202 is utilized as a confirmation (in AND block 208) in the lean discrimination algorithm 84 when the other classification metrics 200, 204, 206 agree in determining the occurrence of a lean event.

[0061]

[0068] The angular acceleration or roll acceleration vs. roll angle classification metric 204 utilizes D_RATE and R_ANGLE to generate an output, which is provided to an AND block 208. As shown, the roll acceleration vs. roll angle classification metric 204 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the roll acceleration vs. roll angle classification metric 204 represents the metric when the vehicle is experiencing a lean rollover event. The roll acceleration vs. roll angle classification metric 204 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that a comparison of roll acceleration vs. roll angle provides a reliable discrimination between lean and bank events. This is because the roll acceleration vs. roll angle classification metric 204 generates a degree of separation in the metric values ​​that is adequate to reliably discriminate between lean and bank events. Thus, the roll acceleration vs. roll angle classification metric 204 is utilized in the lean discrimination algorithm 84 as a positive determination of a lean event.

[0062]

[0069] Pitch rate vs. roll angle classification metric 206 utilizes P_RATE and R_ANGLE to generate an output, which is provided to AND block 208. As shown, pitch rate vs. roll angle classification metric 206 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of pitch rate vs. roll angle classification metric 206 represents the metric when the vehicle is experiencing a bank roll event. Pitch rate vs. roll angle classification metric 206 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that a comparison of pitch rate vs. roll angle provides a reliable discrimination between bank events and bank events. This is because pitch rate vs. roll angle classification metric 206 generates a degree of separation in the metric values ​​that is adequate to reliably discriminate between bank events and bank events. Thus, pitch rate vs. roll angle classification metric 206 is utilized in bank discrimination algorithm 84 as a positive determination of a bank event.

[0063]

[0070] Embankment detection The fill discrimination algorithm 86 is shown in Figure 5. The fill discrimination algorithm 86 is used to determine whether to use the fill threshold (see Figure 3) when deploying an actuatable restraint. The fill discrimination algorithm 86 in Figure 5 is shown for a left roll event, i.e., the vehicle rolls to the left or driver's side. However, it should be appreciated that the algorithm shown in Figure 5 also applies to a right roll event, the only difference being the opposite sign (+ / -) of the values ​​used in the metrics. In other words, the metrics for a right roll event are the same as those shown in Figure 5 except that the signs on each axis for the different metric values ​​are opposite, e.g., negative instead of positive and vice versa.

[0064]

[0071] The fill discrimination algorithm 86 implements four different metrics to discriminate tilt events. The four metrics are: · CCU_1Y_AMA vs R_ANGLE ·CCU_6Z vs R_ANGLE D_RATE vs. R_ANGLE P_RATE vs. R_ANGLE

[0065]

[0072] The USE EMBANKMENT THRESHOLD decision is made at block 232 in response to all of the classification metrics 220, 222, 224, 226 provided to AND block 228 being satisfied, i.e., a Boolean value of 1, herein denoted as ON. The USE EMBANKMENT THRESHOLD decision 232 may be a latched decision, as indicated by LATCH block 230. Thus, once AND block 228 is satisfied, USE EMBANKMENT THRESHOLD 232 is ON and remains ON by LATCH 230 even after the metrics provided to AND block 228 have ceased to be ON. The classification metrics 220, 222, 224, 226 provided to AND block 228 are described in the following paragraphs.

[0066]

[0073] The lateral acceleration vs. roll angle classification metric 220 utilizes CCU_1Y_AMA and R_ANGLE to generate an output, which is provided to an AND block 228. As shown, the lateral acceleration vs. roll angle classification metric 220 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the lateral acceleration vs. roll angle classification metric 220 represents the metric when the vehicle is experiencing an embankment rollover event. The lateral acceleration vs. roll angle classification metric 220 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the lateral acceleration vs. roll angle classification metric 220 does not generate enough separation to reliably distinguish between a pitch event and an embankment event. Therefore, the lateral acceleration vs. roll angle classification metric 220 is utilized as a confirmation (at AND block 228) in the embankment discrimination algorithm 86 when the other classification metrics 222, 224, 226 agree in determining the occurrence of an embankment event.

[0067]

[0074] The vertical acceleration vs. roll angle classification metric 222 utilizes CCU_6ZY_AMA and R_ANGLE to generate an output, which is provided to an AND block 228. As shown, the vertical acceleration vs. roll angle classification metric 222 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the vertical acceleration vs. roll angle classification metric 222 represents the metric when the vehicle is experiencing an embankment rollover event. The vertical acceleration vs. roll angle classification metric 222 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the vertical acceleration vs. roll angle classification metric 222 does not generate enough separation to reliably distinguish between a pitch event and an embankment event. Therefore, the vertical acceleration vs. roll angle classification metric 222 is utilized as a confirmation (at AND block 228) in the embankment discrimination algorithm 86 when the other classification metrics 220, 224, 226 agree in determining the occurrence of an embankment event.

[0068]

[0075] The angular acceleration or roll acceleration vs. roll angle classification metric 224 utilizes D_RATE and R_ANGLE to generate an output, which is provided to an AND block 228. As shown, the roll acceleration vs. roll angle classification metric 224 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the roll acceleration vs. roll angle classification metric 224 represents the metric when the vehicle is experiencing an embankment rollover event. The roll acceleration vs. roll angle classification metric 224 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that a comparison of roll acceleration vs. roll angle provides a reliable discrimination between pitch and embankment events. This is because the roll acceleration vs. roll angle classification metric 224 generates a degree of separation in the metric values ​​that is adequate to reliably discriminate between pitch and embankment events. Thus, the roll acceleration vs. roll angle classification metric 224 is utilized in the embankment discrimination algorithm 86 as a positive determination of an embankment event.

[0069]

[0076] Pitch rate vs. roll angle classification metric 226 utilizes P_RATE and R_ANGLE to generate an output, which is provided to AND block 228. As shown, pitch rate vs. roll angle classification metric 226 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of pitch rate vs. roll angle classification metric 226 represents the metric when the vehicle is experiencing an embankment rollover event. Pitch rate vs. roll angle classification metric 226 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that a comparison of pitch rate vs. roll angle provides a reliable discrimination between a pitch event and an embankment event. This is because pitch rate vs. roll angle classification metric 226 generates a degree of separation in the metric values ​​that is adequate to reliably discriminate between a pitch event and an embankment event. Thus, pitch rate vs. roll angle classification metric 226 is utilized in embankment discrimination algorithm 86 as a positive determination of an embankment event.

[0070]

[0077] Separation of tilt and embankment events From the previous paragraph and looking at FIG. 4 and FIG. 5, it can be seen that the slope and fill discrimination algorithm 84, 86 uses P_RATE and D_RATE to enhance the separation of slope rollover events from fill rollover events. The slope and fill discrimination algorithm 84, 86 uses CCU_1Y_AMA and CCU_6Z_AMA to verify or confirm the discrimination between slope and fill rollover events. Among all types of rollover events, D_RATE for fill rollover is the smallest, so D_RATE can be implemented in the metric to separate fill events from slope events. Therefore, if P_RATE is not available, D_RATE discriminates the fill event and distinguishes it from the slope event, i.e., AND gates 208 and 228 can be three-input gates omitting classification metrics 206 and 226, respectively. However, it should be noted that using both P_RATE and D_RATE, i.e., using all four metrics as shown in FIG. 4 and FIG. 5, is more robust.

[0071]

[0078] Tilt and fill events produce similar lateral accelerations and roll rates. Thus, as shown in Figures 4 and 5, the trigger regions for the lateral acceleration versus roll rate classification metrics 200 and 220 may be similar or identical. Because the lateral acceleration is similar for both events, classification metrics 200 and 220 that compare these values ​​do not provide separation between tilt and fill events. Even though the lateral acceleration CCU_1Y_AMA cannot distinguish between tilt and fill, it behaves predictably and repeatably in response to tilt and fill events and can be used to corroborate or confirm the occurrence of these events.

[0072]

[0079] A pitch event and an embankment event will result in significantly different roll acceleration (D_RATE). Thus, as shown in Figures 4 and 5, the trigger region for the roll acceleration vs. roll rate metric for pitch discrimination 204 is different than the trigger region for embankment discrimination 224. Accordingly, classification metric 204 is ON for pitch events and OFF for embankment events. This in turn allows classification metrics 204 and 224 to discriminate between these events in a predictable, repeatable, and reliable manner.

[0073]

[0080] Roll and bank events also result in significantly different pitch rates (P_RATE). Thus, as shown in Figures 4 and 5, the trigger regions for the pitch rate vs. roll rate metric for roll discrimination 206 are different than the trigger regions for bank discrimination 226. This allows the classification metrics 206 and 226 to discriminate between these events in a predictable, repeatable, and reliable manner.

[0074]

[0081] Embankment and soil events As previously mentioned, an embankment event is an event where one side of a vehicle travels down an embankment on the side of a roadway, causing a rollover. An earth event is an event where a vehicle skidding down a roadway engages earth or other material, trapping the tires / wheels and causing the vehicle to roll over. For example, comparing a left vehicle rollover event, a left embankment rollover event is caused by the left side of the vehicle moving / accelerating downward along an embankment structure, causing a left roll about the vehicle's longitudinal, X-axis. A left earth rollover event is caused by a lateral vehicle movement along the vehicle's lateral, Y-axis, on the left or driver's side, causing an abrupt stop or deceleration, causing a left roll about the vehicle's longitudinal, X-axis. For purposes of providing enhanced occupant protection, it may be advantageous to distinguish an embankment event from an earth event.

[0075]

[0082] Hard soil detection The hard soil discrimination algorithm 88 is shown in Figure 6. The hard soil discrimination algorithm 88 is used to determine whether to use the hard soil threshold (see Figure 3) when deploying an actuatable restraint. The hard soil discrimination algorithm 88 in Figure 6 is shown for a left roll event, i.e., the vehicle rolls to the left or driver's side. However, it should be appreciated that the algorithm shown in Figure 6 also applies to a right roll event, the only difference being the opposite signs (+ / -) of the values ​​used in the metrics. In other words, the metrics for a right roll event are the same as those shown in Figure 6 except that the signs on each axis for the different metric values ​​are opposite, e.g., negative instead of positive and vice versa.

[0076]

[0083] An earth event is an event where a vehicle skids off the road onto the soil. Classifying earth events as hard, medium, and soft by an enhanced discrimination algorithm provides a response tailored to the unique crash characteristics associated with these crash scenarios. A hard earth event can also be categorized as a trip event where the vehicle skids off the road and strikes a curb, causing the vehicle to "trip" and rapidly escalate into a rollover.

[0077]

[0084] The hard soil discrimination algorithm 88 implements four different metrics to discriminate between slope and fill events. The four metrics are: D_RATE vs. R_RATE_2 ·CCU_6Z vs R_ANGLE · CCU_1Y_AMA vs R_ANGLE D_RATE vs. R_ANGLE

[0078]

[0085] The USE HARD SOIL decision is made in block 250 in response to the classification metric 260 provided to AND block 252 and the LATCH HARD SOIL block 254 being satisfied, i.e., a Boolean value of 1, herein denoted as ON. The LATCH HARD SOIL block 254 is a latched decision, meaning that once the AND block 256 is satisfied, the LATCH HARD SOIL 254 is ON and remains ON even after the metrics provided to the AND block 256 have stopped being ON. Classification metrics 262, 264, and 266 are provided to the AND block 256. The classification metrics 260, 262, 264, 266 are described in the following paragraphs.

[0079]

[0086] Angular acceleration or roll acceleration versus roll rate classification metric 260 utilizes D_RATE and R_RATE_2 to generate an output, which is provided to AND block 252. As shown, roll acceleration versus roll rate classification metric 260 is ON when the metric is in the HARD trigger region defined by the solid line of the metric. The trigger region indicated by classification metric 260 is the trigger region of the region (HARD, MID, SOFT) that the metric first enters from the shaded region. In other words, the trigger region is latched in classification metric 260. Thus, if the metric first enters the HARD trigger region and subsequently moves into the MID and / or SOFT trigger region, the HARD trigger region indication remains ON and the MID and / or SOFT trigger region indication remains OFF. The solid line of roll acceleration versus roll rate classification metric 260 represents the metric when the vehicle is experiencing a hard soil rollover event.

[0080]

[0087] A hard soil event, such as a curb trip, produces a large roll acceleration due to the sudden onset of high skid resistance provided by the hard soil surface, i.e., the curb. The roll acceleration vs. roll rate classification metric 260, which is configured to classify this large roll acceleration into the HARD trigger region, provides a reliable discrimination of a hard soil event. In addition, testing has shown that the roll acceleration vs. roll rate classification metric 260 produces a reasonable degree of separation in metric values ​​to reliably discriminate between hard soil and fill events. Thus, the roll acceleration vs. roll rate classification metric 260 may be utilized in the hard soil discrimination algorithm 88 as a positive determination of a hard soil event.

[0081]

[0088] The vertical acceleration vs. roll angle classification metric 262 utilizes CCU_6ZY_AMA and R_ANGLE to generate an output that is provided to AND block 256. As shown, the vertical acceleration vs. roll angle classification metric 262 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the vertical acceleration vs. roll angle classification metric 262 represents the metric when the vehicle is experiencing a hard soil rollover event. The vertical acceleration vs. roll angle classification metric 262 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the vertical acceleration vs. roll angle classification metric 262 does not generate enough separation to reliably distinguish between a hard soil event and a fill soil event. Therefore, the vertical acceleration vs. roll angle classification metric 262 is utilized as a confirmation (in AND block 256) in the hard soil discrimination algorithm 88 when the other classification metrics 264, 266 are consistent in determining the occurrence of a hard soil event.

[0082]

[0089] The lateral acceleration vs. roll angle classification metric 264 utilizes CCU_1Y_AMA and R_ANGLE to generate an output that is provided to AND block 256. As shown, the lateral acceleration vs. roll angle classification metric 264 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the lateral acceleration vs. roll angle classification metric 264 represents the metric when the vehicle is experiencing a hard soil rollover event. The lateral acceleration vs. roll angle classification metric 264 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the lateral acceleration vs. roll angle classification metric 266 does not generate enough separation to reliably distinguish between a hard soil event and a fill event. Therefore, the lateral acceleration vs. roll angle classification metric 266 is utilized (at AND block 256) as a confirmation in the hard soil discrimination algorithm 88 when the other classification metrics 262, 264 agree in determining the occurrence of a hard soil event.

[0083]

[0090] The angular acceleration or roll acceleration vs. roll angle classification metric 266 utilizes D_RATE and R_ANGLE to generate an output, which is provided to AND block 256. As shown, the roll acceleration vs. roll angle classification metric 266 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the roll acceleration vs. roll angle classification metric 256 represents the metric when the vehicle is experiencing a hard soil rollover event. The roll acceleration vs. roll angle classification metric 266 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that a comparison of roll acceleration vs. roll angle provides a reliable discrimination between hard soil events and fill events. This is because the roll acceleration vs. roll angle classification metric 264 generates a degree of separation in the metric values ​​that is adequate to reliably discriminate between hard soil events and fill events. Thus, the roll acceleration vs. roll angle classification metric 264 is utilized in the hard soil discrimination algorithm 88 as a positive determination of a hard soil event.

[0084]

[0091] Intermediate soil discrimination The neutral soil discrimination algorithm 90 is shown in Figure 7. The neutral soil discrimination algorithm 90 is used to determine whether to use the neutral soil threshold (see Figure 3) when deploying an actuatable restraint. The neutral soil discrimination algorithm 90 in Figure 7 is shown for a left roll event, i.e., the vehicle rolls to the left or driver's side. However, it should be appreciated that the algorithm shown in Figure 7 also applies to a right roll event, the only difference being the opposite sign (+ / -) of the values ​​used in the metrics. In other words, the metrics for a right roll event are the same as those shown in Figure 7 except that the signs on each axis for the different metric values ​​are opposite, e.g., negative instead of positive and vice versa.

[0085]

[0092] A soil event is an event in which a vehicle skids off the road onto soil. Classifying soil events as hard, medium, and soft by an enhanced discrimination algorithm provides a response tailored to the unique crash characteristics associated with these crash scenarios. A medium soil event can also be categorized as an event that does not experience as much acceleration as a hard soil or trip event, but does experience greater acceleration than events associated with a soft soil event, such as grass or a grass field. A medium soil event can be an event between a hard soil and a soft soil event, for example, a vehicle skids off the road onto dry, hard packed soil and / or onto gravel, causing a rollover that develops slower than a hard soil event but faster than a soft soil event.

[0086]

[0093] The intermediate soil discrimination algorithm 90 implements four different metrics to discriminate between slope and fill events. The four metrics are: D_RATE vs. R_RATE_2 ·CCU_6Z vs R_ANGLE · CCU_1Y_AMA vs R_ANGLE D_RATE vs. R_ANGLE

[0087]

[0094] The USE MID-SOIL decision is made at block 270 in response to the classification metric 280 provided to AND block 272 and the LATCH MID-SOIL block 274 being satisfied, i.e., a Boolean value of 1, herein denoted as ON. LATCH MID-SOIL block 274 is a latched decision, meaning that once AND block 276 is satisfied, LATCH MID-SOIL 274 turns ON and remains ON even after the metrics provided to AND block 276 stop being ON. Classification metrics 282, 284, and 286 are provided to AND block 276. Classification metrics 280, 282, 284, 286 are described in the following paragraphs.

[0088]

[0095] Angular or roll acceleration versus roll rate classification metric 280 utilizes D_RATE and R_RATE_2 to generate an output that is provided to AND block 272. As shown, roll acceleration versus roll rate classification metric 280 is ON when the metric is in the MID trigger region defined by the solid line of the metric. The trigger region indicated by classification metric 280 is the trigger region of the region (HARD, MID, SOFT) that the metric first enters from the shaded region. In other words, the trigger region is latched at classification metric 280. Thus, if the metric first enters the MID trigger region and subsequently transitions into the HARD and / or SOFT trigger regions, the MID trigger region indication remains ON and the HARD and / or SOFT trigger region indications remain OFF.

[0089]

[0096] A medium soil event, such as hard packed dry soil and / or gravel, results in a roll acceleration of a lower magnitude than that of a hard soil event due to the sudden onset of high siding resistance provided by the medium soil surface. The roll acceleration vs. roll rate classification metric 280 configured to classify this roll acceleration into the MID trigger region provides a reliable discrimination of a medium soil event. In addition, testing has shown that the roll acceleration vs. roll rate classification metric 280 produces a reasonable degree of separation in metric values ​​to reliably discriminate between medium soil and fill soil events. Thus, the roll acceleration vs. roll rate classification metric 280 may be utilized in the medium soil discrimination algorithm 90 as a positive determination of a medium soil event. The solid line of the roll acceleration vs. roll rate classification metric 280 represents the metric when the vehicle is experiencing a medium soil rollover event.

[0090]

[0097] The vertical acceleration vs. roll angle classification metric 282 utilizes CCU_6ZY_AMA and R_ANGLE to generate an output that is provided to the AND block 276. As shown, the vertical acceleration vs. roll angle classification metric 282 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the vertical acceleration vs. roll angle classification metric 282 represents the metric when the vehicle is experiencing a medium soil rollover event. The vertical acceleration vs. roll angle classification metric 282 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the vertical acceleration vs. roll angle classification metric 282 does not generate enough separation to reliably distinguish between medium soil and fill events. Therefore, the vertical acceleration vs. roll angle classification metric 282 is utilized as a confirmation (in the AND block 276) in the medium soil discrimination algorithm 90 when the other classification metrics 284, 286 are consistent in determining the occurrence of a medium soil event.

[0091]

[0098] The lateral acceleration vs. roll angle classification metric 284 utilizes CCU_1Y_AMA and R_ANGLE to generate an output that is provided to the AND block 276. As shown, the lateral acceleration vs. roll angle classification metric 284 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the lateral acceleration vs. roll angle classification metric 284 represents the metric when the vehicle is experiencing a medium soil rollover event. The lateral acceleration vs. roll angle classification metric 284 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the lateral acceleration vs. roll angle classification metric 286 does not generate enough separation to reliably distinguish between medium soil and fill events. Therefore, the lateral acceleration vs. roll angle classification metric 286 is utilized (in the AND block 276) as a confirmation in the medium soil discrimination algorithm 90 when the other classification metrics 282, 284 agree in determining the occurrence of a medium soil event.

[0092]

[0099] The angular acceleration or roll acceleration vs. roll angle classification metric 286 utilizes D_RATE and R_ANGLE to generate an output, which is provided to AND block 276. As shown, the roll acceleration vs. roll angle classification metric 286 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the roll acceleration vs. roll angle classification metric 286 represents the metric when the vehicle is experiencing a medium soil rollover event. The roll acceleration vs. roll angle classification metric 286 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that a comparison of roll acceleration vs. roll angle provides a reliable discrimination between medium soil and fill events. This is because the roll acceleration vs. roll angle classification metric 284 generates a degree of separation in the metric values ​​that is adequate to reliably discriminate between medium soil and fill events. Thus, the roll acceleration vs. roll angle classification metric 284 is utilized in the medium soil discrimination algorithm 90 as a positive determination of a medium soil event.

[0093]

[0100] Soft soil identification The soft soil discrimination algorithm 92 is shown in Figure 8. The soft soil discrimination algorithm 92 is used to determine whether to use the soft soil threshold (see Figure 3) when deploying an actuatable restraint. The soft soil discrimination algorithm 92 in Figure 8 is shown for a left roll event, i.e., the vehicle rolls to the left or driver's side. However, it should be appreciated that the algorithm shown in Figure 8 also applies to a right roll event, the only difference being the opposite signs (+ / -) of the values ​​used in the metrics. In other words, the metrics for a right roll event are the same as those shown in Figure 8, except that the signs on each axis for the different metric values ​​are opposite, e.g., negative instead of positive, and vice versa.

[0094]

[0101] A soil event is an event in which a vehicle skids off the road onto soil. Classifying soil events as hard, medium, and soft provides responses tailored to the unique crash characteristics associated with these crash scenarios. Soft soil events can also be categorized as events that do not experience as much acceleration as medium soil or hard soil or trip events. A soft soil event occurs, for example, when a vehicle skids off the road onto grass or grass, causing a rollover that develops more slowly than both hard soil and medium soil events.

[0095]

[0102] The soft soil discrimination algorithm 92 implements four different metrics to discriminate between tilt and fill events. The four metrics are: D_RATE vs. R_RATE_2 ·CCU_6Z vs R_ANGLE · CCU_1Y_AMA vs R_ANGLE D_RATE vs. R_ANGLE

[0096]

[0103] The USE SOFT SOIL decision is made at block 300 in response to the classification metric 310 provided to AND block 302 and the LATCH SOFT SOIL block 304 being satisfied, i.e., a Boolean value of 1, herein denoted as ON. The LATCH SOFT SOIL block 304 is a latched decision, meaning that once the AND block 306 is satisfied, the LATCH SOFT SOIL 304 is ON and remains ON even after the metrics provided to the AND block 306 have stopped being ON. Classification metrics 312, 314, and 316 are provided to the AND block 306. The classification metrics 310, 312, 314, 316 are described in the following paragraphs.

[0097]

[0104] Angular or roll acceleration versus roll rate classification metric 310 utilizes D_RATE and R_RATE_2 to generate an output that is provided to AND block 302. As shown, roll acceleration versus roll rate classification metric 310 is ON when the metric is in the SOFT trigger region defined by the solid line of the metric. The trigger region indicated by classification metric 310 is the trigger region of the region (HARD, MID, SOFT) that the metric first enters from the shaded region. In other words, the trigger region is latched at classification metric 310. Thus, if the metric first enters the SOFT trigger region and subsequently moves into the HARD and / or MID trigger regions, the SOFT trigger region indication remains ON and the HARD and / or MID trigger region indications remain OFF.

[0098]

[0105] A soft soil event, such as hard packed dry soil and / or gravel, results in a roll acceleration of a lower magnitude than that of a hard soil event due to the sudden onset of high siding resistance provided by the soft soil surface. The roll acceleration vs. roll rate classification metric 310, configured to classify this roll acceleration into the SOFT trigger region, provides a reliable discrimination of a soft soil event. In addition, testing has shown that the roll acceleration vs. roll rate classification metric 310 produces a reasonable degree of separation in metric values ​​to reliably discriminate between soft soil and fill events. Thus, the roll acceleration vs. roll rate classification metric 310 is utilized in the soft soil discrimination algorithm 92 as a positive determination of a soft soil event. The solid line of the roll acceleration vs. roll rate classification metric 310 represents the metric when the vehicle is experiencing a soft soil rollover event.

[0099]

[0106] The vertical acceleration vs. roll angle classification metric 312 utilizes CCU_6ZY_AMA and R_ANGLE to generate an output that is provided to the AND block 306. As shown, the vertical acceleration vs. roll angle classification metric 312 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the vertical acceleration vs. roll angle classification metric 312 represents the metric when the vehicle is experiencing a soft soil rollover event. The vertical acceleration vs. roll angle classification metric 312 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the vertical acceleration vs. roll angle classification metric 312 does not generate enough separation to reliably distinguish between soft soil and fill events. Therefore, the vertical acceleration vs. roll angle classification metric 312 is utilized as a confirmation (in the AND block 306) in the soft soil discrimination algorithm 92 when the other classification metrics 314, 316 agree in determining the occurrence of a soft soil event.

[0100]

[0107] The lateral acceleration vs. roll angle classification metric 314 utilizes CCU_1Y_AMA and R_ANGLE to generate an output that is provided to AND block 306. As shown, the lateral acceleration vs. roll angle classification metric 314 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the lateral acceleration vs. roll angle classification metric 314 represents the metric when the vehicle is experiencing a soft soil rollover event. The lateral acceleration vs. roll angle classification metric 314 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that the lateral acceleration vs. roll angle classification metric 316 does not generate enough separation to reliably distinguish between soft soil and fill events. Therefore, the lateral acceleration vs. roll angle classification metric 316 is utilized as a confirmation (in AND block 306) in the soft soil discrimination algorithm 92 when the other classification metrics 312, 314 agree in determining the occurrence of a soft soil event.

[0101]

[0108] The angular acceleration or roll acceleration vs. roll angle classification metric 316 utilizes D_RATE and R_ANGLE to generate an output, which is provided to AND block 306. As shown, the roll acceleration vs. roll angle classification metric 316 is ON when the metric is in the shaded trigger region bounded by the dashed lines. The solid line of the roll acceleration vs. roll angle classification metric 316 represents the metric when the vehicle is experiencing a soft soil rollover event. The roll acceleration vs. roll angle classification metric 316 is a non-latching metric, meaning that the metric is ON only when the metric is in the trigger region. Testing has shown that a comparison of roll acceleration vs. roll angle provides a reliable discrimination between soft soil and fill events. This is because the roll acceleration vs. roll angle classification metric 314 generates a degree of separation in the metric values ​​that is adequate to reliably discriminate between soft soil and fill events. Thus, the roll acceleration vs. roll angle classification metric 314 is utilized in the soft soil discrimination algorithm 92 as a positive determination of a soft soil event.

[0102]

[0109] Rollover detection From the above, it will be appreciated that the enhanced discrimination algorithm shown in Figures 4-8 and described herein can be implemented in a vehicle safety system to discriminate between a tilt rollover event (Figure 4), an embankment rollover event (Figure 5), a hard soil rollover event (Figure 6), a medium soil rollover event (Figure 7) and a soft soil rollover event (Figure 8). As described above, these discriminations are performed with a high degree of mutual exclusivity, i.e., discrimination of any one of these events is exclusive to the others with a high degree of accuracy. Thus, the enhanced discrimination algorithm is capable of identifying and classifying a rollover event into one of these categories. Based on the classified rollover event, the vehicle safety system can select thresholds for deploying actuatable restraint devices, such as airbags and seat belts, thereby improving the level of occupant protection provided by the vehicle safety system.

[0103]

[0110] From the above description of the present invention, one skilled in the art will appreciate that the described vehicle safety system and method implements an algorithm that can distinguish a bank rollover event from a slope rollover event and can also distinguish a bank rollover event from a slope rollover event. One skilled in the art will further recognize improvements, changes, and modifications to the disclosed system and method that fall within the spirit and scope of the present invention. These improvements, changes, and / or modifications are intended to be covered by the appended claims. <Additional Notes> [Form 1] A vehicle safety system comprising: an actuatable restraint device for assisting in protecting a vehicle occupant; a controller for controlling actuation of the actuatable restraint device in response to a vehicle rollover event; Equipped with the controller is configured to execute a discrimination algorithm including at least one classification metric utilizing at least one of a vehicle pitch rate (P_RATE) and a vehicle roll acceleration (D_RATE) to discriminate at least one of a bank rollover event and a slope rollover event from a bank rollover event, the discrimination algorithm determining a classification of the vehicle rollover event, the classification being one of a bank rollover event, a slope rollover event, a slope rollover event, and a bank rollover event; The vehicle safety system, wherein the controller is further configured to select a deployment threshold for deploying the actuatable restraint device, the deployment threshold corresponding to the classification of the vehicle rollover event. [Form 2] 2. The vehicle safety system of claim 1, wherein the at least one classification metric includes a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE). [Form 3] In the vehicle safety system according to aspect 1, the at least one classification metric includes a classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE); A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a bank rollover event from a slope rollover event. [Form 4] In the vehicle safety system according to aspect 3, the at least one classification metric further comprises a classification metric evaluating vehicle pitch rate (P_RATE) versus vehicle roll angle (R_ANGLE); A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle pitch rate (P_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a bank rollover event from a slope rollover event. [Form 5] In the vehicle safety system according to aspect 4, the at least one classification metric further comprises a classification metric evaluating vehicle lateral acceleration running average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE); 11. A vehicle safety system, comprising: a controller configured to execute the classification metric evaluating a vehicle lateral acceleration running average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE) to verify the discrimination between a bank rollover event and a slope rollover event. [Form 6] In the vehicle safety system according to aspect 4, the at least one classification metric further comprises a classification metric evaluating vehicle vertical acceleration running average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE); 11. A vehicle safety system, comprising: a controller configured to execute the classification metric evaluating a vehicle vertical acceleration running average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE) to verify the discrimination between a bank rollover event and a slope rollover event. [Form 7] In the vehicle safety system according to aspect 1, the at least one classification metric includes a classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE); A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a dirt rollover event from an bank rollover event. [Form 8] 8. The vehicle safety system of claim 7, wherein the discrimination algorithm further comprises a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2); A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2) to distinguish a dirt rollover event from an bank rollover event. [Form 9] 9. The vehicle safety system of claim 8, wherein the controller is configured to execute the classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2) to distinguish between a hard soil rollover event, a medium soil rollover event, and a soft soil rollover event. [Form 10] In the vehicle safety system according to aspect 8, the at least one classification metric further comprises a classification metric evaluating vehicle lateral acceleration running average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE); The vehicle safety system, wherein the controller is configured to execute the classification metric evaluating a vehicle lateral acceleration running average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE) to distinguish a dirt rollover event from a bank rollover event. [Form 11] In the vehicle safety system according to aspect 8, the at least one classification metric further comprises a classification metric evaluating vehicle vertical acceleration running average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE); 11. A vehicle safety system, comprising: a controller configured to execute the classification metric evaluating a vehicle vertical acceleration running average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE) to verify the discrimination between a dirt rollover event and a bank rollover event. [Form 12] In the vehicle safety system described in form 1, the controller is configured to execute a deployment threshold metric to determine whether to activate the actuatable restraint device, the deployment threshold metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE), and the controller is configured to deploy the actuatable restraint device in response to the deployment threshold metric exceeding the deployment threshold. [Form 13] In the vehicle safety system according to aspect 1, an accelerometer for sensing vehicle lateral acceleration and providing a signal indicative of the sensed vehicle lateral acceleration (CCU_1Y); an accelerometer for sensing vehicle vertical acceleration and providing a signal indicative of the sensed vehicle vertical acceleration (CCU_6Z); a roll rate sensor for sensing a vehicle roll rate value and providing a signal indicative of the sensed vehicle roll rate value (CCU_4R); and wherein the controller further comprises: determining a vehicle lateral acceleration running average (CCU_1Y_AMA) from said signal indicative of sensed vehicle lateral acceleration (CCU_1Y); determining a vehicle vertical acceleration running average (CCU_6Z_AMA) from said signal indicative of sensed vehicle vertical acceleration (CCU_6Z); determining a vehicle roll acceleration (D_RATE) from said signal indicative of a sensed vehicle roll rate value (CCU_4R); determining a vehicle roll angle (R_ANGLE) from said signal indicative of a sensed vehicle roll rate value (CCU_4R); A vehicle safety system configured to perform vehicle metric calculations to: [Form 14] In the vehicle safety system described in form 1, the vehicle safety system further comprises a pitch rate sensor for sensing a vehicle pitch rate value and providing a signal (CCU_5P) indicative of the sensed vehicle pitch rate, and the controller is configured to perform vehicle metric calculations to determine a vehicle pitch rate (P_RATE) from the signal (CCU_5P) indicative of the sensed vehicle pitch rate. [Form 15] In the vehicle safety system described in form 1, the actuatable restraint device comprises at least one of a seat belt anchor pretensioner, a seat belt retractor pretensioner, a curtain airbag, a thorax airbag, a side airbag, an emergency notification, a door unlock command, and a high voltage powertrain cutoff command. [Form 16] In the vehicle safety system described in form 1, the controller is further configured to issue at least one of an emergency notification, a door unlock command, and a high voltage powertrain cut-off command in response to activating the operable restraint device. [Explanation of symbols]

[0104] 10 Vehicle Safety Systems 20 Operable restraint devices 22 Other vehicle safety features, emergency notifications 50 Central Control Unit (CCU) 52 Accelerometer 54 Accelerometer 56 Pitch rate sensor 58 Roll rate sensor 60 Central Processing Unit (CPU) 70 Vehicle Metric Calculations 80 Enhanced discrimination algorithm 82 Rollover Detection Algorithm 84 Slope Discrimination Algorithm 86 Embankment Discrimination Algorithm 88 Hard soil discrimination algorithm 90 Intermediate soil discrimination algorithm 92 Soft soil discrimination algorithm 100 Analog-to-Digital Converter (ADC) Functions 102 Rail / Bias Functions 104 High-pass filter (HPF) function 106 Low-pass filter (LPF) function 108 Rate Shift Function 110 Integral High-Pass Filter (IHPF) Function 112 Low-pass filter (LPF) function 120 Moving Average Function 122 Moving Average Function 124 Difference Functions 130 Analog-to-Digital Converter (ADC) Functions 132 Rail / Bias Functions 134 High-pass filter (HPF) function 136 Low-pass filter (LPF) function 140 Analog-to-Digital Converter (ADC) Functions 142 Rail / Bias Functions 144 High Pass Filter (HPF) Function 146 Low-pass filter (LPF) function 148 Moving Average Function Block 150 Moving Average Function Block 160 Analog-to-Digital Converter (ADC) Functions 162 Rail / Bias Functions 164 High Pass Filter (HPF) Functions 166 Low-pass filter (LPF) function 168 Moving Average Blocks 170 Moving Average Blocks 200 Classification Metrics 202 Classification Metrics 204 Classification Metrics 206 Classification Metrics 208 AND Block 210 LATCH block 212 USE RAMP THRESHOLD block 220 Classification Metrics 222 Classification Metrics 224 Classification Metrics 226 Classification Metrics 228 AND Block 230 LATCH block 232 USE EMBANKMENT THRESHOLD BLOCK 250 USE HARD SOIL BLOCK 252 AND Block 254 LATCH HARD SOIL BLOCK 256 AND block 260 Classification Metrics 262 Classification Metrics 264 Classification Metrics 266 Classification Metrics 270 USE MID-SOIL BLOCK 272 AND Block 274 LATCH MID-SOIL BLOCK 276 AND Block 280 Classification Metrics 282 Classification Metrics 284 Classification Metrics 286 Classification Metrics 300 USE SOFT SOIL BLOCK 302 AND Block 304 LATCH SOFT SOIL BLOCK 306 AND Block 310 Classification Metrics 312 Classification Metrics 314 Classification Metrics 316 Classification Metrics

Claims

1. A vehicle safety system, comprising: an actuatable restraint device for assisting in protecting a vehicle occupant; a controller for controlling actuation of the actuatable restraint device in response to a vehicle rollover event; Equipped with the controller is configured to execute a discrimination algorithm including at least one classification metric utilizing at least one of a vehicle pitch rate (P_RATE) and a vehicle roll acceleration (D_RATE) to discriminate at least one of a bank rollover event and a pitch roll event from a bank rollover event, the discrimination algorithm determining a classification of the vehicle rollover event, the classification being one of a bank rollover event, a pitch roll event, a bank rollover event, and the controller is further configured to select a deployment threshold for deploying the actuatable restraint device, the deployment threshold corresponding to the classification of the vehicle rollover event; The at least one classification metric includes a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE).

2. 2. The vehicle safety system according to claim 1, A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a bank rollover event from a slope rollover event.

3. 3. The vehicle safety system according to claim 2, the at least one classification metric further comprises a classification metric evaluating vehicle pitch rate (P_RATE) versus vehicle roll angle (R_ANGLE); A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle pitch rate (P_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a bank rollover event from a slope rollover event.

4. 4. The vehicle safety system according to claim 3, the at least one classification metric further comprises a classification metric evaluating vehicle lateral acceleration moving average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE); 11. A vehicle safety system, comprising: a controller configured to execute the classification metric evaluating vehicle lateral acceleration moving average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE) to verify the discrimination between a bank rollover event and a slope rollover event.

5. 4. The vehicle safety system according to claim 3, the at least one classification metric further comprises a classification metric evaluating vehicle vertical acceleration running average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE); 11. A vehicle safety system, comprising: a controller configured to execute the classification metric evaluating a vehicle vertical acceleration running average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE) to verify the discrimination between a bank rollover event and a slope rollover event.

6. 2. The vehicle safety system according to claim 1, A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll angle (R_ANGLE) to distinguish a dirt rollover event from a bank rollover event.

7. 7. The vehicle safety system of claim 6, wherein the discrimination algorithm further comprises a classification metric that evaluates vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2); A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2) to distinguish a dirt rollover event from a bank rollover event.

8. 8. The vehicle safety system of claim 7, wherein the controller is configured to execute the classification metric evaluating vehicle roll acceleration (D_RATE) versus vehicle roll rate (R_RATE_2) to distinguish between hard soil rollover events, medium soil rollover events, and soft soil rollover events.

9. 8. The vehicle safety system according to claim 7, the at least one classification metric further comprises a classification metric evaluating vehicle lateral acceleration moving average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE); A vehicle safety system, wherein the controller is configured to execute the classification metric evaluating vehicle lateral acceleration running average (CCU_1Y_AMA) versus vehicle roll angle (R_ANGLE) to distinguish a dirt rollover event from a bank rollover event.

10. 8. The vehicle safety system according to claim 7, the at least one classification metric further comprises a classification metric evaluating vehicle vertical acceleration running average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE); 11. A vehicle safety system, comprising: a controller configured to execute the classification metric evaluating a vehicle vertical acceleration running average (CCU_6Z_AMA) versus vehicle roll angle (R_ANGLE) to verify the discrimination between a dirt rollover event and a bank rollover event.

11. A vehicle safety system, comprising: an actuatable restraint device for assisting in protecting a vehicle occupant; a controller for controlling actuation of the actuatable restraint device in response to a vehicle rollover event; Equipped with the controller is configured to execute a discrimination algorithm including at least one classification metric utilizing at least one of a vehicle pitch rate (P_RATE) and a vehicle roll acceleration (D_RATE) to discriminate at least one of a bank rollover event and a pitch roll event from a bank rollover event, the discrimination algorithm determining a classification of the vehicle rollover event, the classification being one of a bank rollover event, a pitch roll event, a bank rollover event, and the controller is further configured to select a deployment threshold for deploying the actuatable restraint device, the deployment threshold corresponding to the classification of the vehicle rollover event; 1. A vehicle safety system comprising: a vehicle control system configured to: determine whether to activate an actuatable restraint device by executing a deployment threshold metric; the deployment threshold metric evaluating a vehicle roll acceleration (D_RATE) versus a vehicle roll angle (R_ANGLE); and the controller configured to deploy the actuatable restraint device in response to the deployment threshold metric exceeding the deployment threshold.

12. A vehicle safety system, comprising: an actuatable restraint device for assisting in protecting a vehicle occupant; a controller for controlling actuation of the actuatable restraint device in response to a vehicle rollover event; Equipped with the controller is configured to execute a discrimination algorithm including at least one classification metric utilizing at least one of a vehicle pitch rate (P_RATE) and a vehicle roll acceleration (D_RATE) to discriminate at least one of a bank rollover event and a pitch roll event from a bank rollover event, the discrimination algorithm determining a classification of the vehicle rollover event, the classification being one of a bank rollover event, a pitch roll event, a bank rollover event, and the controller is further configured to select a deployment threshold for deploying the actuatable restraint device, the deployment threshold corresponding to the classification of the vehicle rollover event; an accelerometer for sensing vehicle lateral acceleration and providing a signal indicative of the sensed vehicle lateral acceleration (CCU_1Y); an accelerometer for sensing vehicle vertical acceleration and providing a signal indicative of the sensed vehicle vertical acceleration (CCU_6Z); a roll rate sensor for sensing a vehicle roll rate value and providing a signal indicative of the sensed vehicle roll rate value (CCU_4R); and wherein the controller further comprises: determining a vehicle lateral acceleration running average (CCU_1Y_AMA) from said signal indicative of sensed vehicle lateral acceleration (CCU_1Y); determining a vehicle vertical acceleration running average (CCU_6Z_AMA) from said signal indicative of sensed vehicle vertical acceleration (CCU_6Z); determining a vehicle roll acceleration (D_RATE) from said signal indicative of a sensed vehicle roll rate value (CCU_4R); determining a vehicle roll angle (R_ANGLE) from said signal indicative of a sensed vehicle roll rate value (CCU_4R); A vehicle safety system configured to perform vehicle metric calculations to:

13. A vehicle safety system, comprising: an actuatable restraint device for assisting in protecting a vehicle occupant; a controller for controlling actuation of the actuatable restraint device in response to a vehicle rollover event; Equipped with the controller is configured to execute a discrimination algorithm including at least one classification metric utilizing at least one of a vehicle pitch rate (P_RATE) and a vehicle roll acceleration (D_RATE) to discriminate at least one of a bank rollover event and a pitch roll event from a bank rollover event, the discrimination algorithm determining a classification of the vehicle rollover event, the classification being one of a bank rollover event, a pitch roll event, a bank rollover event, and the controller is further configured to select a deployment threshold for deploying the actuatable restraint device, the deployment threshold corresponding to the classification of the vehicle rollover event; A vehicle safety system further comprising a pitch rate sensor for sensing a vehicle pitch rate value and providing a signal (CCU_5P) indicative of a sensed vehicle pitch rate, the controller being configured to perform a vehicle metric calculation to determine a vehicle pitch rate (P_RATE) from the signal (CCU_5P) indicative of a sensed vehicle pitch rate.

14. 10. The vehicle safety system of claim 1, wherein the actuatable restraint device comprises at least one of a seat belt anchor pretensioner, a seat belt retractor pretensioner, a curtain airbag, a thorax airbag, a side airbag, an emergency notification, a door unlock command, and a high voltage powertrain cut off command.

15. 10. The vehicle safety system of claim 1, wherein the controller is further configured to issue at least one of an emergency notification, a door unlock command, and a high voltage powertrain shutoff command in response to actuating the actuatable restraint device.

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