Method and system for controlling actuatable protection devices with enhanced roll-over discrimination

Abstract

The invention relates to a method for controlling actuation of an actuatable restraint device in response to a roll-over event to help protect a vehicle occupant, the method being implemented in a controller of a vehicle safety system comprising the actuatable restraint device. To implement the method, the controller is configured to perform a roll discrimination metric that discriminates whether a ramp rollover event or a bank rollover event has occurred in response to a magnitude of a vehicle roll rate (R_RATE) exceeding a predetermined threshold roll rate (R_RATE). The controller is further configured to perform a switch metric that is operable to decrease the predetermined threshold roll rate (R_RATE) in response to a magnitude of a vehicle pitch rate (P_RATE) exceeding a predetermined threshold pitch rate (P_RATE). The invention also relates to a vehicle safety system.

Description

Technical Field

[0001] The present invention relates to a method and system for controlling a vehicle actuable occupant protection device, and more particularly to an enhanced discrimination method and system for classifying several specific types of rollover vehicle collision events. Background Technology

[0002] Vehicle safety systems include a central control unit, sometimes called the airbag control unit (“ACU”), which uses sensors, both local and remote to the ACU, to detect collision events involving the vehicle and determine whether these events warrant activation of actuated restraint devices, such as airbags and seatbelt retractors. Sensors used by the ACU may include accelerometers and other sensors such as impact sensors, seatbelt buckle switches, seat pressure switches, steering angle sensors, etc. Using data from these sensors, the ACU can determine that a vehicle collision event has occurred and can execute a discrimination algorithm to classify the collision event into a specific type. The ACU can then activate the actuated restraint devices based on the specific type of collision event.

[0003] For vehicle safety systems, it is desirable to distinguish between various collision events that a vehicle may be involved in. “Distinguishing” a collision event may mean classifying it into a specific type and differentiating it from other types. If a vehicle safety system can distinguish or identify a collision event as a specific type, it can actuate actuable restraints in a manner appropriate to that specific type of collision event. As used herein, “collision event” can be used to encompass a variety of events involving a vehicle. For example, a collision event might be a collision or impact in which the vehicle collides, strikes, or otherwise engages with a structure of a different type. These collision events could be collisions with deformable obstacles (such as another vehicle) or collisions with non-deformable obstacles (such as trees or utility poles). As another example, a collision event may also involve events such as rollover events, where a vehicle impact results from the vehicle rolling over. A rollover event might result from the vehicle skidding and striking a curb, sliding or otherwise moving off the curb and falling into an embankment or ditch, or sliding or otherwise moving off the curb and climbing a slope (such as a hillside).

[0004] Vehicle safety systems can be configured or adapted to distinguish between events where the application of actuated restraints is expected (“applied events”) and events where the application of actuated restraints is not expected (“unapplied events”). Collision determination requires identifying the event type, such as deformable obstacles, non-deformable obstacles, frontal impact, rear impact, side impact, oblique impact, offset impact, rollover, etc. Collision determination also requires determining the severity of the collision and implementing safety functions, which manifest as checks or authorizations to ensure the safe application of actuated restraints.

[0005] Based on the above, it will be understood that it may be desirable to control the actuation and timing of actuable restraint devices in a safety system in response to the type and / or severity of a collision event involving the vehicle. To determine which occupant protection devices to actuate in response to a sensed collision event, the safety system may implement a collision assessment process to differentiate between types of collision events. If the identified collision event reaches or exceeds a severity threshold, and the safety functions are appropriate, the actuable restraint devices can be actuated in a manner corresponding to the determined event type.

[0006] Over the years, safety standards have been revised and updated to "push the envelope" in automotive safety. As a result, automakers have been required to continuously improve the safety of their products to keep up with these standards. As standards become more stringent, safety systems adapt and become more complex and robust. Through the development of vehicle safety systems, it has been found that crash classification is one of the key aspects that helps determine system effectiveness. If a safety system can accurately and robustly identify crash scenarios defined by safety standards, then that safety system can be tailored to provide the best possible outcome for the occupants involved in the accidents that the standard was designed to address.

[0007] Although vehicle safety systems capable of differentiating between various collision events have been developed, further classification and differentiation between collision events remains necessary so that vehicle safety systems can take appropriate action. Collision events that may require differentiation could be of different types, such as rollover events or events that could lead to rollover.

[0008] A rollover collision is an event that may warrant the activation of safety devices such as side airbags (curtain airbags, chest airbags) and / or seatbelt pretensioners. Rollover collisions can occur in a variety of scenarios. For example, a vehicle may lose control and skid off the road onto adjacent grass / land, fall into an embankment, plunge into a ditch, or climb a slope or hillside. As another example, a vehicle may lose control and skid into a lower obstacle (such as a curb). In any of these scenarios, the severity of the resulting rollover collision may warrant the activation of one or more vehicle safety devices. Summary of the Invention

[0009] According to one aspect, a vehicle safety system includes an actuable restraint device for assisting in the protection of vehicle occupants, and a controller for controlling the actuation of the actuable restraint device in response to a vehicle rollover event. The controller is configured to perform a roll discrimination metric that determines whether a slope rollover event or an embankment rollover event has occurred in response to a vehicle roll rate (R_RATE) exceeding a predetermined threshold roll rate (R_RATE). The controller is also configured to perform a switching metric operable to reduce the predetermined threshold roll rate (R_RATE) in response to a vehicle pitch rate (P_RATE) exceeding the predetermined threshold pitch rate (P_RATE).

[0010] According to another aspect, alone or in combination with other aspects described herein, the roll discrimination metric can assess the roll rate (R_RATE) to detect the occurrence of a ramp event in response to the magnitude of the roll rate (R_RATE) exceeding a ramp event threshold, or to detect the occurrence of an embankment event in response to the magnitude of the roll rate (R_RATE) exceeding an embankment event threshold.

[0011] According to another aspect, alone or in combination with other aspects described herein, in response to the magnitude of the pitch rate (P_RATE) exceeding the predetermined threshold pitch rate (P_RATE), the roll discrimination metric can evaluate the roll rate (R_RATE) to detect the occurrence of a ramp event in response to the magnitude of the roll rate (R_RATE) exceeding the switching ramp event threshold, or to detect the occurrence of an embankment event in response to the magnitude of the roll rate (R_RATE) exceeding the switching embankment event threshold.

[0012] According to another aspect, alone or in combination with other aspects described herein, this roll discrimination metric can evaluate the roll rate (R_RATE) versus the vehicle roll angle (R_ANGLE).

[0013] According to another aspect, alone or in combination with other aspects described herein, the switching metric can evaluate the pitch rate (P_RATE) to detect the occurrence of a switching ramp event threshold condition in response to the magnitude of the pitch rate (P_RATE) exceeding a ramp pitch switching threshold, or to detect the occurrence of a switching embankment event threshold condition in response to the magnitude of the pitch rate (P_RATE) exceeding an embankment pitch switching threshold.

[0014] According to another aspect, alone or in combination with other aspects described herein, this switching metric can evaluate the pitch rate (P_RATE) versus the vehicle roll angle (R_ANGLE).

[0015] According to another aspect, alone or in combination with other aspects described herein, the controller may be further configured to execute at least one of a slope discrimination algorithm and an embankment discrimination algorithm, the slope discrimination algorithm including a slope classification portion configured to classify slope events, and the embankment discrimination algorithm including an embankment classification portion configured to classify embankment events. The controller may be configured to apply the actuable constraint device in response to the tilt discrimination metric determining that a slope rollover event has occurred and the slope classification portion classifying the slope event. The controller may also be configured to apply the actuable constraint device in response to the embankment discrimination metric determining that an embankment rollover event has occurred and the embankment classification portion classifying the embankment event.

[0016] According to another aspect, alone or in combination with other aspects described herein, the system may further include an accelerometer for sensing vehicle lateral acceleration and providing a signal indicating the sensed vehicle lateral acceleration; an accelerometer for sensing vehicle vertical acceleration and providing a signal indicating the sensed vehicle vertical acceleration; a roll sensor for sensing vehicle roll values ​​and providing a signal indicating the sensed vehicle roll values; and a pitch sensor for sensing vehicle pitch values ​​and providing a signal indicating the sensed vehicle pitch. The controller may be configured to use the signals provided by these accelerometers, the roll rate sensor, and the pitch rate sensor to perform the roll discrimination metric and the switching metric.

[0017] According to another aspect, alone or in combination with other aspects described herein, these actuable restraint devices may include at least one of seat belt anchor pretensioners, seat belt retractor pretensioners, curtain airbags, chest airbags, and side airbags.

[0018] According to another aspect, a method for controlling the actuation of an actuable restraint device in response to a vehicle rollover event includes determining whether a slope rollover event or an embankment rollover event has occurred in response to the magnitude of a vehicle roll rate (R_RATE) exceeding a predetermined threshold roll rate (R_RATE). The method further includes reducing the predetermined threshold roll rate (R_RATE) in response to the magnitude of a vehicle pitch rate (P_RATE) exceeding a predetermined threshold pitch rate (P_RATE).

[0019] According to another aspect, either alone or in combination with other aspects described herein, determining whether a slope rollover event or an embankment rollover event has occurred may include at least one of the following operations: assessing the roll rate (R_RATE) to detect the occurrence of a slope event in response to the magnitude of the roll rate (R_RATE) exceeding a slope event threshold, and assessing the roll rate (R_RATE) to detect the occurrence of an embankment event in response to the magnitude of the roll rate (R_RATE) exceeding an embankment event threshold.

[0020] According to another aspect, alone or in combination with other aspects described herein, the method may include evaluating the roll rate (R_RATE) in response to the magnitude of the pitch rate (P_RATE) exceeding the predetermined threshold pitch rate (P_RATE) to detect the occurrence of at least one of the following events: detecting the occurrence of a ramp event in response to the magnitude of the roll rate (R_RATE) exceeding a switching ramp event threshold, and detecting the occurrence of an embankment event in response to the magnitude of the roll rate (R_RATE) exceeding a switching embankment event threshold.

[0021] According to another aspect, either alone or in combination with other aspects described herein, determining whether a slope rollover event or an embankment rollover event has occurred may include assessing the roll rate (R_RATE) in relation to the vehicle roll angle (R_ANGLE).

[0022] According to another aspect, alone or in combination with other aspects described herein, reducing the predetermined threshold roll rate (R_RATE) in response to the magnitude of the vehicle pitch rate (P_RATE) exceeding the predetermined threshold pitch rate (P_RATE) may include evaluating the pitch rate (P_RATE) to detect the occurrence of a switching slope event threshold condition in response to the magnitude of the pitch rate (P_RATE) exceeding the slope pitch switching threshold, or detecting the occurrence of a switching embankment event threshold condition in response to the magnitude of the pitch rate (P_RATE) exceeding the embankment pitch switching threshold.

[0023] According to another aspect, alone or in combination with other aspects described herein, reducing the predetermined threshold roll rate (R_RATE) in response to the magnitude of the vehicle pitch rate (P_RATE) exceeding the predetermined threshold roll rate (P_RATE) may include evaluating the pitch rate (P_RATE) in relation to the vehicle roll angle (R_ANGLE).

[0024] According to another aspect, alone or in combination with other aspects described herein, the method may further include classifying the rollover event as a ramp event or an embankment event. The method may further include applying the actuable restraint device in response to classifying the rollover event as a ramp event and determining that a ramp rollover event has occurred. The method may also include applying the actuable restraint device in response to classifying the rollover event as an embankment event and determining that an embankment rollover event has occurred.

[0025] According to another aspect, alone or in combination with other aspects described herein, a vehicle safety system may include an actuable restraint device for helping to protect vehicle occupants, and a controller for controlling the actuation of the actuable restraint device according to the methods described herein. Attached Figure Description

[0026] The foregoing and other features and advantages of the invention will become apparent to those skilled in the art after considering the following description of the invention and the accompanying drawings, in which:

[0027] Figure 1 It is a schematic diagram illustrating the vehicle and the signals obtained from the sensor architecture deployed therein.

[0028] Figure 2 It is a block diagram illustrating the vehicle's safety system.

[0029] Figure 3 It is a block diagram illustrating the measurement calculations implemented in a vehicle safety system.

[0030] Figure 4 It is a diagram illustrating the discriminant and switching metrics implemented in a vehicle safety system to determine when a hill-over event has occurred.

[0031] Figure 5 It is a schematic block diagram illustrating the classification metrics and deployment logic for ramp rollover events implemented in a vehicle safety system.

[0032] Figure 6 It is a diagram illustrating the discriminant and switching metrics implemented in a vehicle safety system to determine when an embankment rollover event has occurred.

[0033] Figure 7It is a schematic block diagram illustrating the classification metrics and deployment logic for embankment rollover events implemented in a vehicle safety system. Detailed Implementation

[0034] This invention relates to a vehicle safety system implementing an enhanced discrimination algorithm that can distinguish and classify ramp rollover events and embankment rollover events. The algorithm uses pitch rate sensing to switch classification thresholds for faster and more accurate identification of ramp rollover and embankment rollover events.

[0035] Because this invention relates to enhanced discrimination of ramp rollover events and embankment rollover events, vehicle safety systems are shown and described herein as including certain components and implementing algorithms necessary to perform these specific enhanced discrimination functions. Those skilled in the art will understand that vehicle safety systems may include components other than those shown and described herein, and may perform discrimination functions other than those shown and described herein.

[0036] refer to Figure 1 According to one example configuration, vehicle 12 includes a vehicle safety system 10, which includes a central control unit, referred to herein as an airbag control unit (ACU) 50. ACU 50 is operable to actuate one or more actuable restraint devices 20, such as left / right seatbelt pretensioners (anchors and / or retractors), left / right curtain airbags, left / right chest airbags, and left / right lateral airbags. ACU 50 is also operable to control the actuation of other protective devices, such as front airbags and knee airbags.

[0037] The ACU 50 includes one or more sensors operable to provide signals indicative of the vehicle's linear acceleration and / or angular acceleration and / or rate of movement in different directions and relative to different vehicle axes. These sensors may be locally mounted in or on the ACU 50 itself, or remotely connected to the ACU, for example, via wires. These vehicle axes include an X-axis that extends longitudinally within the vehicle along its forward / rearward direction of travel. A Y-axis extends laterally within the vehicle, perpendicular to the X-axis. A Z-axis extends vertically within the vehicle, perpendicular to both the X-axis and Y-axis.

[0038] The X-axis, Y-axis, and Z-axis are in Figure 1 The intersection is shown at ACU 50. This is because ACU 50 includes sensors for measuring the movement (i.e., acceleration) of vehicle 12 relative to these axes. These movements are... Figure 1 The symbol (+ / -) indicates the sign (positive or negative) assigned to the motion by the safety system 10.

[0039] The vehicle safety system 10 is configured to interpret motion along the X-axis as positive (acceleration) from front to back and negative (deceleration) from back to front. Motion along the Y-axis is interpreted as positive from right to left and negative from left to right. Motion along the Z-axis is interpreted as positive in the downward direction and negative in the upward direction.

[0040] The vehicle safety system 10 is configured to interpret motion (i.e., roll) about the X-axis as positive for left roll and negative for right roll. Motion (i.e., pitch) about the Y-axis is interpreted as positive for pitch down (dive) and negative for pitch up (pounce). Motion (i.e., yaw) about the Z-axis is interpreted as positive for yaw when turning left and negative for yaw when turning right.

[0041] refer to Figure 2 The ACU 50 includes an accelerometer 52 for sensing the vehicle's lateral (Y-axis) acceleration (ACU_Y). The ACU 50 also includes an accelerometer 54 for sensing the vehicle's vertical (Z-axis) acceleration (ACU_Z). Although not used in the discrimination algorithm disclosed herein, the ACU 50 may also include an accelerometer 56 for sensing the vehicle's longitudinal (X-axis) acceleration (ACU_X).

[0042] ACU 50 also includes a pitch rate sensor 60 for sensing the vehicle pitch rate value (PITCH), i.e., the pitch rate around the vehicle's Y-axis. ACU 50 further includes a roll rate sensor 62 for sensing the vehicle roll rate value (ROLL), i.e., the roll rate around the vehicle's X-axis. Although not used in the discrimination algorithm disclosed herein, ACU 50 may also include a yaw rate sensor 64 for sensing the yaw rate around the vehicle's Z-axis.

[0043] It may be desirable to position the sensors on or near the respective axes along or around which they sense vehicle motion. Since the sensors can be locally mounted on the ACU 50, it may be desirable to mount the ACU at or near the vehicle's center of gravity, through which the vehicle's X, Y, and Z axes pass. The location of the ACU 50 at or near the vehicle's center of gravity is not critical, and the ACU 50 can be located in other locations within the vehicle.

[0044] The hardware and software configurations of the ACU implemented in the vehicle safety system are known in the art. Therefore, a detailed description of the hardware configuration of the ACU 50 is not required for a person skilled in the art to understand and recognize the vehicle safety system 10. Figure 1The ACU 50 includes a central processing unit (CPU), such as a microcomputer, which is configured to receive signals ACU_X, ACU_Y, ACU_Z, ROLL, PITCH, and YAW from the respective sensors, perform vehicle measurement calculations 70 on these signals, and execute an enhanced discrimination algorithm 80 using the calculated measurements.

[0045] The vehicle metrics generated by calculation 62 include: • Average lateral Y-axis acceleration of the vehicle (AMA_Y). • Average vertical Z-axis acceleration of the vehicle (AMA_Z). • Vehicle roll differential rate, i.e. roll acceleration (D_RATE). • Vehicle pitch rate (P_RATE). • Vehicle pitch angle (P_ANGLE). • Vehicle roll rate (R_RATE). • Vehicle roll rate 2 (R_RATE_2). • Vehicle roll angle (R_ANGLE).

[0046] The enhanced discrimination algorithm 80 includes a normal rollover discrimination algorithm 82, a slope discrimination algorithm 84, an embankment discrimination algorithm 86, a hard soil discrimination algorithm 88, a moderate soil discrimination algorithm 90, and a soft soil discrimination algorithm 92. The ACU 50 is configured to perform vehicle measurement calculations 70 and the enhanced discrimination algorithm 80, and to determine which actuable constraint devices 20 (if any) should be actuated. For the purposes of this disclosure, the discrimination algorithms for the slope event 84 and the embankment event 86 are novel, inventive, and disclosed in detail.

[0047] Figure 3 The vehicle measurement calculation 70 performed by ACU 50 is shown. Figure 2 The elements of the vehicle measurement calculation 70 shown are referred to herein as “functions” performed internally by the ACU 50. roll rate measurement

[0048] The ACU 50 employs signal conditioning including an analog-to-digital converter (ADC) to convert the ROLL, PITCH, ACU_Y, and ACU_Z signals from various accelerometers into digital signals. The ACU can also perform track checking and bias adjustment. For example... Figure 3As shown, the digitized and biased roll rate is passed to, for example, a high-pass filter (HPF) function 104 that can be selected to have a time constant that causes the filter function to be reset after a predetermined time period (e.g., T = 8 seconds). The high-pass filtered roll rate generated at HPF function 104 is then passed to a low-pass filter (LPF) function 106 that generates a roll rate metric R_RATE, which has an indication in the enhancement discrimination algorithm 80 (see...). Figure 2 The value of the vehicle roll rate (i.e., angular velocity) implemented in the algorithm 80 is then passed to the 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 produce a value indicating a defined relative roll angle of the vehicle. The IHPF function 110 also performs high-pass filtering on the R_RATE signal. The IHPF function 110 generates the value in the enhanced discrimination algorithm 80 (see...). Figure 2 The metric R_ANGLE implemented in ).

[0049] R_ANGLE indicates the vehicle's normalized roll angle, a measure of the vehicle's relative angular rotation in response to a sensed roll rate. The IHPF function 110 can reset R_ANGLE based on the time constant of the high-pass filter function, such that R_ANGLE provides an indication of angular rotation during the occurrence of the detected roll rate. Therefore, R_ANGLE may not indicate the vehicle's actual angular orientation relative to the ground. In this way, the determination of a vehicle rollover condition does not necessarily depend on the determination of the vehicle's initial angular orientation relative to the ground or road.

[0050] The high-pass filtered roll of the tilt rate generated at HPF function 104 is also passed to moving average function 120, and then to moving average function 122. Each moving average function 120, 122 can be, for example, adjustable to select the number of samples, for example, 1 to 32 samples. Moving average functions 120, 122 smooth the changes in the tilt rate, thereby producing a result in the enhanced discrimination algorithm 80 (see...). Figure 2 The metric R_RATE_2 implemented in )

[0051] R_RATE_2 is provided to the difference function 124, in which the difference between the current sample and the previous sample is compared. This produces a differential roll rate metric D_RATE, which indicates the rate of change of the roll rate, i.e., acceleration. This roll acceleration D_RATE is the angular acceleration of the vehicle about the vehicle's X-axis. The roll acceleration D_RATE is used in the enhanced discrimination algorithm 80 (see...). Figure 2 Implemented in ). Pitch rate measurement

[0052] like Figure 3 As shown, the digitized and biased pitch rate PITCH is passed to, for example, a high-pass filter (HPF) function 134 that can be selected with a time constant that causes the filter function to be reset after a predetermined time period (e.g., T = 8 seconds). The high-pass filtered pitch rate generated at HPF function 134 is then passed to low-pass filter (LPF) function 136. LPF function 136 is generated in the enhancement discrimination algorithm 80 (see...). Figure 2 The pitch rate metric P_RATE implemented in ) has a value indicating the vehicle's pitch rate (i.e., angular velocity). Lateral acceleration measurement

[0053] like Figure 3 As shown, the digitized and biased lateral acceleration ACU_Y is passed to, for example, a high-pass filter (HPF) function 144, which can be selected to have a time constant that causes the filter function to be reset after a predetermined time period (e.g., T = 8 seconds). The high-pass filtered lateral acceleration ACU_Y generated at HPF function 144 is passed to a low-pass filter (LPF) function 146. The low-pass filtered lateral acceleration ACU_Y value generated at LPF function 146 is passed to moving average boxes 148 and 150, which generate lateral acceleration metrics ACU_Y_AMA and ACU_Y_AMA_SAFE, respectively. The number of samples included in each of the moving average functions 148 and 150 can be adjusted within a predetermined range, such as 1 to 32 samples. ACU_Y_AMA and ACU_Y_AMA_SAFE are used in the enhanced discrimination algorithm 80 (see...). Figure 2 The average lateral acceleration shift implemented in ). Vertical acceleration measurement

[0054] like Figure 3As shown, the digitized and biased vertical acceleration ACU_Z is passed to, for example, a high-pass filter (HPF) function 164 with a time constant that causes the filter function to be reset after a predetermined time period (e.g., T = 8 seconds). The high-pass filtered lateral acceleration ACU_Z generated at HPF function 164 is passed to a low-pass filter (LPF) function 166. The low-pass filtered lateral acceleration ACU_Z value generated at LPF function 166 is passed to moving average boxes 168 and 170, which generate lateral acceleration metrics ACU_Z_AMA and ACU_Z_AMA_SAFE, respectively. The number of samples included in each of the moving average functions 168 and 170 can be adjusted within a predetermined range, such as 1 to 32 samples. ACU_Z_AMA and ACU_Z_AMA_SAFE are used in the enhanced discrimination algorithm 80 (see...). Figure 2 The average lateral acceleration shift implemented in ). Roll detection

[0055] The enhanced discrimination algorithm 80 implements the ability to differentiate between various types of rollover events, which allows for the customization of thresholds that trigger the application of the actuable constraint device 20. Some examples of these thresholds are... Figure 4 Displayed in the middle. For example... Figure 4 As shown, the enhanced discrimination algorithm 80 includes discrimination metrics 200, which employ various thresholds to determine whether the sensed vehicle roll characteristics indicate various different rollover event classifications. For example... Figure 4 As shown, the threshold metric is applied based on a comparison of R_RATE and R_ANGLE. Figure 4 The threshold determination demonstrates left lateral tilt (i.e., tilt toward the driver's side) as indicated by the R_RATE and R_ANGLE values ​​in the positive direction. Right lateral tilt (i.e., tilt toward the passenger's side) as indicated by the R_RATE and R_ANGLE values ​​in the opposite (i.e., negative) direction is also shown.

[0056] like Figure 4 As shown, soft soil rollover events are classified with the lowest threshold for triggering the application of actuated restraint devices. Hard soil conditions have the next lowest threshold for triggering the application of actuated restraint devices, followed by moderate soil, embankments, slopes, and normal rollover. These application threshold triggers can be latched, in which case, when the roll angle is equal to zero or the measurement enters... Figure 4 When the reset box is shown, the latch can be reset.

[0057] The application trigger threshold is highest for normal conditions (i.e., where other thresholds are not categorized). Normal conditions can also be latched, in which case the latch is triggered when the roll rate equals zero or the metric enters... Figure 4When the reset box is shown, the latch can be reset. Although in Figure 4 The thresholds are shown in a specific order of size, but it should be understood that the sizes associated with the thresholds can vary. For example, the threshold for hard soil can be lower than that for soft soil, etc. However, the normal threshold is usually the highest threshold. Enhanced ramp discrimination using pitch rate switching

[0058] For example Figure 4 As shown, the discrimination metric 200 includes a ramp switching threshold, indicated by a dashed line. Advantageously, the ramp switching threshold is smaller than the corresponding non-switching threshold, i.e., the ramp threshold. A ramp switching threshold with a lower threshold size can be used to detect ramp events more quickly in time, which can improve the speed and responsiveness of the vehicle safety system 10 in responding to ramp rollover events.

[0059] like Figure 4 As shown, the enhanced discrimination algorithm 80 also includes switching metrics 202, which are used to enable or "switch" the discrimination metrics 200 to implement ramp switching thresholds. Figure 4 As shown, the switching metric 202 is based on a comparison of P_RATE and R_ANGLE. Looking at the switching metric 202, the ramp switching threshold can be met when the vehicle is pitching upwards (i.e., the vehicle is tilting upwards), which is consistent with the vehicle driving up a ramp (such as up a hill or road obstacle / separator).

[0060] like Figure 4 As shown, the enhanced discrimination algorithm 80 implements Boolean discrimination logic based on the results or outputs of discrimination metric 200 and switching metric 202. This Boolean logic forms part of the ramp discrimination algorithm 84 implemented by the enhanced discrimination algorithm 80. Since ramp discrimination is involved, discrimination metric 200 can output a ramp threshold ON indication (box 206) and / or a ramp switching threshold ON indication (box 208). These indications 206, 208 are output by these metrics in response to discrimination metric 200 exceeding their respective thresholds (as indicated by the star symbols at 210 and 212, respectively). In response to switching metric 202 exceeding the ramp pitch switching threshold (as indicated by the star symbol at 216), these metrics output a ramp pitch threshold ON indication (box 214).

[0061] The ramp discrimination algorithm 84 is operable to determine that a ramp rollover collision event has occurred, and outputs a ramp discrimination ON indication (box 222) in response to either of the two conditions being met at box 220. The ramp discrimination ON indication 222 occurs due to either the ramp threshold ON indication 206 or both the ramp switching threshold ON indication 208 and the ramp pitch threshold ON indication 214 (as shown at box 218). Advantageously, when implementing the switching metric 202, the enhanced discrimination algorithm 80 can utilize vehicle pitch rate sensing to lower the ramp discrimination threshold, thereby identifying ramp rollover collision events earlier (i.e., faster) than when using vehicle roll rate alone for discrimination. Ramp Classification

[0062] Figure 5 The slope classification portion of the slope discrimination algorithm 84, implemented by the enhanced discrimination algorithm 80, is shown. The slope classification portion of the slope discrimination algorithm 84 uses vehicle metrics to classify rollover collision events as slope events. If via slope discrimination (see...) Figure 4 If confirmed, the ramp detection algorithm 84 issues a command (see box 246) to apply the vehicle safety device in a predetermined manner corresponding to the identified ramp event.

[0063] For left-side rollover incidents (i.e., in the case of a slope incident, the vehicle tilts to the left or to the driver's side), the following is shown: Figure 5 The ramp classification part of the ramp discrimination algorithm 84. However, it should be understood that... Figure 5 The algorithm shown also applies to right-flipping events, the only difference being that the sign (+ / -) of the values ​​used in the classification metric is reversed. In other words, the classification metric used for right-flipping events will be... Figure 5 The classification measures shown are the same, except that the signs of the corresponding axes for different values ​​within a classification measure will be reversed, for example, positive becomes negative, and vice versa.

[0064] The ramp classification part of the ramp discrimination algorithm 84 implements four different classification measures to classify ramp events. These four ramp classification measures are: • AMA_Y versus R_ANGLE (metric 232) • AMA_Z versus R_ANGLE (metric 234) • R_RATE versus R_ANGLE (metric 236) • D_RATE versus R_ANGLE (metric 238)

[0065] Lateral acceleration to roll angle classification metric 232 uses AMA_Y and R_ANGLE to generate the output fed to box 240. As shown, the metric is triggered when lateral acceleration to roll angle classification metric 232 exceeds a threshold (typically indicated by a dashed line) and enters the shaded trigger region. This trigger is typically indicated by an asterisk. When metric 232 is in the trigger region, it remains ON. The solid line in lateral acceleration to roll angle classification metric 232 represents the metric when the vehicle is experiencing a hill-start overturning event. Lateral acceleration to roll angle classification metric 200 is a non-latching metric, meaning it is ON only when it is in the trigger region.

[0066] The vertical acceleration to roll angle classification metric 234 uses AMA_Z and R_ANGLE to generate the output fed to box 240. As shown, the metric 234 is triggered when it exceeds a threshold (typically indicated by a dashed line) and enters a shaded trigger region. This trigger is typically indicated by an asterisk. When the metric 234 is within the shaded trigger region defined by dashed lines, the metric remains ON. It should be noted that there is no limit to the size of AMA_Z for the trigger region of the metric 234, which is indicated by the dashed threshold indicating the absence of a trigger region. The solid line in the vertical acceleration to roll angle classification metric 234 represents the metric when the vehicle is experiencing a hill-climb rollover event. The vertical acceleration to roll angle classification metric 234 is a non-latching metric, meaning that the metric is ON only when it is within the trigger region.

[0067] The roll rate to roll angle classification metric 236 uses R_RATE and R_ANGLE to generate the output fed to box 240. As shown, the metric is triggered when the roll rate to roll angle classification metric 236 exceeds a threshold (typically indicated by a dashed line) and enters a shaded trigger region. This trigger is typically indicated by an asterisk. When the metric 236 is within the shaded trigger region defined by dashed lines, the metric remains ON. It should be noted that there is no limit to the size of R_RATE for the trigger region of the metric 236, which is indicated by the dashed threshold indicating the absence of a trigger region. The solid line in the roll rate to roll angle classification metric 236 represents the metric when the vehicle is experiencing a hill-start rollover event. The roll rate to roll angle classification metric 236 is a non-latching metric, meaning that the metric is ON only when it is within the trigger region.

[0068] The angular acceleration or roll acceleration to roll angle classification metric 238 uses D_RATE and R_ANGLE to generate the output fed to box 240. As shown, the metric is ON when the roll acceleration to roll angle classification metric 238 exceeds a threshold (typically indicated by a dashed line) and enters a shaded trigger region. This trigger is typically indicated by an asterisk. The metric remains ON when it is within the shaded trigger region defined by dashed lines. The solid lines in the roll acceleration to roll angle classification metric 238 represent the metric when the vehicle is experiencing a hill-start overturning event. The roll acceleration to roll angle classification metric 238 is a non-latching metric, meaning it is ON only when it is within the trigger region.

[0069] The ramp classification part of ramp discrimination algorithm 84 implements Boolean logic to determine whether to issue a safety device ramp application command 246. For example... Figure 5 As shown, when box 244 is ON, a safety device ramp application command 246 is issued. This is in response to the ramp being determined to be ON (box 222 – see...). Figure 4 And ramp classification is ON (box 242), and box 244 is ON. In response to all four ramp classification metrics 232, 234, 236, and 238 being ON, box 240 is ON, and ramp classification box 242 is ON. Ramp classification box 242 can be latched until the tilt angle is equal to zero or falls into the reset box (see [link]). Figure 4 )Inside.

[0070] Therefore, it is understandable that the ramp discrimination algorithm 84 implemented in the enhanced discrimination algorithm 80 is operable in response to a rollover event that is classified as a ramp event. Figure 5 It was also classified as a ramp incident. Figure 4 The safety device ramp application command 246 is issued. As explained above, the judgment is made by switching the pitch rate, so the ramp rollover event can be identified earlier, and therefore the safety device ramp application command 246 can be issued earlier. Enhanced embankment discrimination using pitch rate switching

[0071] The enhanced discrimination algorithm 80, implemented by the vehicle safety system 10, also uses pitch rate sensing to perform enhanced embankment discrimination. This in Figure 6 As shown in the figure. Enhanced embankment discrimination using pitch rate switching and the above reference. Figure 4 The described enhanced slope discrimination using pitch rate switching is similar. In fact, the discrimination and switching metrics used to perform enhanced embankment discrimination can be similar to... Figure 4 The same metrics are implemented, except that an embankment switching threshold is added to the discriminant metric and an embankment pitch switching threshold is added to the switching metric. Therefore, for simplicity, Figure 6The discriminant metric and switching metric in the diagram are shown as... Figure 4 The metrics shown are the same. However, those skilled in the art will understand that the metrics used to enhance embankment discrimination and the metrics used for pitch rate sensing may be separate from and / or different from the metrics used for slope discrimination / switching.

[0072] refer to Figure 6 The enhanced discrimination algorithm 80 implements discrimination metrics 300, which include an embankment switching threshold, shown as a dashed line. Advantageously, the embankment switching threshold is smaller than the corresponding non-switching threshold, i.e., the embankment threshold. The switching embankment threshold with a lower threshold size can be used to identify embankment events more quickly in time, which can improve the speed and responsiveness of the vehicle safety system 10 in responding to embankment rollover collision events.

[0073] like Figure 6 As shown, the enhanced discrimination algorithm 80 also includes switching metrics 302, which are used to enable or "switch" the discrimination metrics 300 to implement the embankment switching threshold. Figure 6 As shown, the switching metric 302 is based on a comparison of P_RATE and R_ANGLE. Looking at the switching metric 302, the embankment switching threshold can be met under positive P_RATE (i.e., the vehicle is pitching down (diving)), which is consistent with the vehicle entering the embankment (such as entering a hillside or ditch).

[0074] like Figure 6 As shown, the enhanced discrimination algorithm 80 implements Boolean discrimination logic based on the results or outputs of discrimination metric 300 and switching metric 302. Since embankment discrimination is involved, discrimination metric 300 can output an embankment threshold ON indication (box 306) and / or an embankment switching threshold ON indication (box 308). These indications 306, 308 are output by these metrics in response to discrimination metric 300 exceeding their respective thresholds (as indicated by the star symbols at 310 and 312, respectively). In response to switching metric 302 exceeding the embankment pitch switching threshold (as indicated by the star symbol at 316), these metrics output an embankment pitch threshold ON indication (box 314).

[0075] The embankment discrimination algorithm 86 is operable to determine that an embankment rollover collision event has occurred, and outputs an embankment discrimination ON indication (box 322) in response to either of two conditions being met at box 320. The embankment discrimination ON indication 322 occurs due to either the embankment threshold ON indication 306 or both the embankment switching threshold ON indication 308 and the embankment pitch threshold ON indication 314 (as shown in box 318). Advantageously, when implementing the switching metric 302, the enhanced discrimination algorithm 80 can utilize vehicle pitch rate sensing to lower the embankment discrimination threshold, thereby identifying the embankment rollover collision event earlier (i.e., faster) than when using vehicle roll rate alone for discrimination. Embankment Classification

[0076] Figure 7 This illustrates the embankment classification portion of the embankment discrimination algorithm 86, implemented by the enhanced discrimination algorithm 80. The embankment classification portion of the embankment discrimination algorithm 86 uses vehicle metrics to classify rollover collision events as embankment events. If via embankment discrimination (see...) Figure 6 If confirmed, the embankment discrimination algorithm 86 issues a command (see box 346) to apply the vehicle safety device in a predetermined manner corresponding to the identified embankment event.

[0077] For left-side rollover incidents (i.e., in the case of an embankment incident, the vehicle tilts to the left or to the driver's side), the following is shown: Figure 7 The embankment classification part of the embankment discrimination algorithm 86. However, it should be understood that... Figure 7 The algorithm shown also applies to right-flipping events, the only difference being that the sign (+ / -) of the values ​​used in the classification metric is reversed. In other words, the classification metric used for right-flipping events will be... Figure 7 The classification measures shown are the same, except that the signs of the corresponding axes for different values ​​within a classification measure will be reversed, for example, positive becomes negative, and vice versa.

[0078] The embankment classification part of Algorithm 86 implements four different classification measures to classify embankment events. These four embankment classification measures are: • AMA_Y versus R_ANGLE (metric 332) • AMA_Z versus R_ANGLE (metric 334) • R_RATE versus R_ANGLE (metric 336) • D_RATE versus R_ANGLE (metric 338)

[0079] The lateral acceleration to roll angle classification metric 332 uses AMA_Y and R_ANGLE to generate the output fed into box 340. As shown, the metric is triggered when the lateral acceleration to roll angle classification metric 332 exceeds a threshold (typically indicated by a dashed line) and enters a shaded trigger region. This trigger is typically indicated by an asterisk. When the metric 332 is within the shaded trigger region defined by the dashed line, the metric remains ON. The solid line in the lateral acceleration to roll angle classification metric 332 represents the metric when the vehicle is experiencing an embankment rollover event. The lateral acceleration to roll angle classification metric 300 is a non-latching metric, meaning that the metric is ON only when it is within the trigger region.

[0080] The vertical acceleration to roll angle classification metric 334 uses AMA_Z and R_ANGLE to generate the output fed to box 340. As shown, the metric is triggered when the vertical acceleration to roll angle classification metric 334 exceeds a threshold (typically indicated by a dashed line) and enters a shaded trigger region. This trigger is typically indicated by an asterisk. When the metric 334 is within the shaded trigger region defined by dashed lines, the metric remains ON. It should be noted that there is no limit to the size of AMA_Z for the trigger region of the metric 334, which is indicated by the dashed threshold indicating the absence of a trigger region. The solid line in the vertical acceleration to roll angle classification metric 334 represents the metric when the vehicle is experiencing an embankment rollover event. The vertical acceleration to roll angle classification metric 334 is a non-latching metric, meaning that the metric is ON only when it is within the trigger region.

[0081] The roll rate to roll angle classification metric 336 uses R_RATE and R_ANGLE to generate the output fed to box 340. As shown, the metric is triggered when the roll rate to roll angle classification metric 336 exceeds a threshold (typically indicated by a dashed line) and enters a shaded trigger region. This trigger is typically indicated by an asterisk. When the metric 336 is within the shaded trigger region defined by dashed lines, the metric remains ON. It should be noted that there is no limit to the size of R_RATE for the trigger region of the metric 336, which is indicated by the dashed threshold indicating the absence of a trigger region. The solid line in the roll rate to roll angle classification metric 336 represents the metric when the vehicle is experiencing an embankment rollover event. The roll rate to roll angle classification metric 336 is a non-latching metric, meaning that the metric is ON only when it is within the trigger region.

[0082] The angular acceleration or roll acceleration to roll angle classification metric 338 uses D_RATE and R_ANGLE to generate the output fed to box 340. As shown, the metric is ON when the roll acceleration to roll angle classification metric 338 exceeds a threshold (typically indicated by a dashed line) and enters a shaded trigger region. This trigger is typically indicated by an asterisk. The metric remains ON while it is within the shaded trigger region defined by dashed lines. The solid lines in the roll acceleration to roll angle classification metric 338 represent the metric when the vehicle is experiencing an embankment rollover event. The roll acceleration to roll angle classification metric 338 is a non-latching metric, meaning it is ON only when it is within the trigger region.

[0083] The embankment classification part of the embankment discrimination algorithm 86 implements Boolean logic to determine whether to issue the safety device embankment application command 346. For example... Figure 7 As shown, when box 344 is ON, a safety device embankment application command 346 is issued. This is in response to the embankment being determined to be ON (box 322 – see...). Figure 6And embankment classification is ON (box 342), and box 344 is ON. In response to all four embankment classification metrics 332, 334, 336, and 338 being ON, box 340 is ON, and embankment classification box 342 is ON. Embankment classification box 342 can be latched until the tilt angle is equal to zero or falls into the reset box (see [link]). Figure 6 )Inside.

[0084] Therefore, it is understandable that the embankment discrimination algorithm 86, implemented by the enhanced discrimination algorithm 80, is operable in response to a rollover event that is classified as an embankment event. Figure 7 It was also classified as an embankment incident. Figure 6 The safety device embankment application command 346 is issued. As explained above, the judgment is made by switching the pitch rate, so the embankment overturning event can be identified earlier, and therefore the safety device embankment application command 346 can be issued earlier.

[0085] Based on the above description of the invention, those skilled in the art will understand that the described vehicle safety systems and methods implement algorithms that can use thresholds determined by pitch rate switching to distinguish between ramp rollover events and embankment rollover events, thereby improving system responsiveness. Those skilled in the art will also recognize improvements, variations, and modifications to the disclosed systems and methods that fall within the spirit and scope of the invention. The appended claims are intended to cover such improvements, variations, and / or modifications.

Claims

1. A vehicle safety system, comprising: Actuable restraint devices used to help protect vehicle occupants; as well as A controller for controlling the actuation of the actuable restraint device in response to a vehicle rollover event; The controller is configured to execute a roll discrimination metric, which determines whether a slope rollover event or an embankment rollover event has occurred in response to the vehicle roll rate (R_RATE) exceeding a predetermined threshold roll rate; and The controller is further configured to execute a switching metric operable to reduce the predetermined threshold roll rate in response to the magnitude of the vehicle pitch rate (P_RATE) exceeding the predetermined threshold pitch rate. The switching metric evaluates the vehicle pitch rate (P_RATE) to detect a slope switching event threshold condition when the vehicle pitch rate (P_RATE) is negative and its magnitude exceeds the slope pitch switching threshold, or when the vehicle pitch rate (P_RATE) is positive and its magnitude exceeds the embankment pitch switching threshold, and a road embankment switching event threshold condition is detected.

2. The vehicle safety system as claimed in claim 1, wherein, The roll discrimination metric evaluates the vehicle roll rate (R_RATE) as follows: A hill start event is detected in response to the vehicle roll rate (R_RATE) exceeding a hill start event threshold, or An embankment event is detected in response to the vehicle roll rate (R_RATE) exceeding the embankment event threshold.

3. The vehicle safety system as described in claim 2, wherein, When the switching metric reduces the predetermined threshold roll rate in response to the vehicle pitch rate (P_RATE) exceeding the predetermined threshold pitch rate, the roll discrimination metric uses the reduced predetermined threshold roll rate to evaluate the vehicle roll rate (R_RATE) to: A ramp event is detected in response to the vehicle roll rate (R_RATE) exceeding the ramp event threshold, or An embankment event is detected in response to the vehicle roll rate (R_RATE) exceeding the embankment event threshold.

4. The vehicle safety system as claimed in claim 1, wherein, The roll discrimination metric evaluates the correspondence between the vehicle roll rate (R_RATE) and the vehicle roll angle (R_ANGLE).

5. The vehicle safety system as claimed in claim 1, wherein, The controller is further configured to execute at least one of a slope discrimination algorithm and an embankment discrimination algorithm, the slope discrimination algorithm including a slope classification part configured to classify slope events, and the embankment discrimination algorithm including an embankment classification part configured to classify embankment events. The controller is configured to apply the actuable restraint device in response to the rollover metric determining a ramp rollover event and the ramp classification section classifying the ramp event; and The controller is configured to apply the actuable constraint device in response to the tilt discrimination metric determining that an embankment rollover event has occurred and the embankment classification section classifying the embankment event.

6. The vehicle safety system of claim 1, further comprising: An accelerometer used to sense lateral acceleration of a vehicle and provide a signal indicating the sensed lateral acceleration of the vehicle; An accelerometer used to sense the vertical acceleration of a vehicle and provide a signal indicating the sensed vertical acceleration of the vehicle; A roll sensor for sensing vehicle roll values ​​and providing a signal indicating the sensed vehicle roll values; and a pitch sensor for sensing vehicle pitch values ​​and providing a signal indicating the sensed vehicle pitch. The controller is configured to use signals provided by the accelerometer, the roll sensor, and the pitch sensor to perform the roll discrimination metric and the switching metric.

7. The vehicle safety system as claimed in claim 1, wherein, The actuable restraint device includes at least one of a seatbelt anchor pretensioner, a seatbelt retractor pretensioner, a curtain airbag, a chest airbag, and a side airbag.

8. A method for controlling the actuation of an actuable restraint device in response to a vehicle rollover event, the method comprising: The system determines whether a slope rollover event or an embankment rollover event occurs in response to the vehicle roll rate (R_RATE) exceeding a predetermined threshold roll rate. as well as The predetermined threshold roll rate is reduced in response to the vehicle pitch rate (P_RATE) exceeding the predetermined threshold pitch rate. Specifically, reducing the predetermined threshold roll rate in response to the vehicle pitch rate (P_RATE) exceeding a predetermined threshold pitch rate includes evaluating the vehicle pitch rate (P_RATE) to: detect the occurrence of a slope switching event threshold condition in response to the vehicle pitch rate (P_RATE) being negative and the magnitude of the vehicle pitch rate (P_RATE) exceeding a slope pitch switching threshold, or detect the occurrence of a embankment switching event threshold condition in response to the vehicle pitch rate (P_RATE) being positive and the magnitude of the vehicle pitch rate (P_RATE) exceeding an embankment pitch switching threshold.

9. The method of claim 8, wherein, Determining whether a slope collapse event or an embankment collapse event involves at least one of the following operations: The vehicle roll rate (R_RATE) is evaluated to detect a slope event in response to the magnitude of the vehicle roll rate (R_RATE) exceeding a slope event threshold; and The vehicle roll rate (R_RATE) is evaluated to detect the occurrence of an embankment event in response to the magnitude of the vehicle roll rate (R_RATE) exceeding the embankment event threshold.

10. The method of claim 9, wherein after the predetermined threshold roll rate is reduced in response to the magnitude of the vehicle pitch rate (P_RATE) exceeding the predetermined threshold pitch rate, the reduced predetermined threshold roll rate is used to evaluate the vehicle roll rate (R_RATE) to detect at least one of the following events: A ramp event is detected in response to the vehicle roll rate (R_RATE) exceeding a ramp event threshold; and An embankment event is detected in response to the vehicle roll rate (R_RATE) exceeding the embankment event threshold.

11. The method of claim 8, wherein, Determining whether a slope rollover event or an embankment rollover event occurs involves an assessment based on the correlation between the vehicle roll rate (R_RATE) and the vehicle roll angle (R_ANGLE).

12. The method of claim 8, further comprising: Rollover incidents are classified as either slope incidents or embankment incidents. The actuable restraint device is applied in response to classifying the rollover event as a ramp event and determining that a ramp rollover event has occurred. as well as The actuable restraint device is applied in response to classifying the rollover event as an embankment event and determining that an embankment rollover event has occurred.

13. A vehicle safety system, comprising: Actuable restraint devices used to help protect vehicle occupants; as well as A controller for controlling the actuation of the actuable constraint device according to the method as described in claim 8.

14. The vehicle safety system of claim 13, further comprising: An accelerometer used to sense lateral acceleration of a vehicle and provide a signal indicating the sensed lateral acceleration of the vehicle; An accelerometer used to sense the vertical acceleration of a vehicle and provide a signal indicating the sensed vertical acceleration of the vehicle; A roll sensor for sensing vehicle roll values ​​and providing a signal indicating the sensed vehicle roll values; and a pitch sensor for sensing vehicle pitch values ​​and providing a signal indicating the sensed vehicle pitch. The controller is configured to use signals provided by the accelerometer, the roll sensor, and the pitch sensor to perform roll discrimination and switching measurements.

15. The system of claim 14, wherein, The actuable restraint device includes at least one of a seatbelt anchor pretensioner, a seatbelt retractor pretensioner, a curtain airbag, a chest airbag, and a side airbag.

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