System and procedure for determining the driving style of a vehicle

Abstract

System for determining the driving behavior of a vehicle (10), wherein the system comprises: Processor (30) comprising an input (36) configured to receive lateral acceleration data from at least one onboard lateral acceleration sensor, wherein the processor (30) is configured (i) to calculate an output signal (125) from the received lateral acceleration data, and (ii) to compare the output signal (125) with at least one output threshold value to determine the driving behavior of the vehicle (10), and Processor (30) comprising an output (38) configured to send a control signal (127) to prevent the vehicle (10) from lowering its ride height, the control signal indicating the vehicle's (10) driving style, wherein the processor (30) has at least one exponentially weighted moving average filter (46) configured to calculate a moving average of the lateral acceleration data at predetermined intervals and to assign exponential weights to the calculated moving averages to calculate the output signal (125), and wherein the processor (30) is configured to apply a gain value to the output signal (125) each time the lateral acceleration data exceeds the at least one lateral acceleration threshold value for a predetermined period, and the amplified output signal (125) decays according to the exponentially weighted moving average filter (46) applied to the lateral acceleration data.

Description

TECHNICAL AREA

[0001] The present disclosure relates to improvements in vehicle handling and, in particular, but not exclusively, to reducing the impairment of the vehicle's driving dynamics. Aspects of the invention relate to a system and a method for determining the driving style of a vehicle, and to a vehicle comprising a system for determining the driving style of a vehicle. STATE OF THE ART

[0002] The ground clearance or ride height of a vehicle can be changed by adjusting its suspension. Lowering a vehicle's ride height offers many advantages. For example, it is known that a vehicle's aerodynamic performance can be improved when the body sits lower to the surface it is driving over. This is because the reduced airflow between the vehicle's chassis and the surface leads to reduced drag. This, in turn, can improve the vehicle's fuel efficiency.

[0003] Lowering the ride height can also improve the vehicle's traction and / or handling. The lowered center of gravity reduces longitudinal and lateral weight transfer during dynamic maneuvers, resulting in less change in tire contact pressure, which is known to improve grip. A lower center of gravity also reduces the likelihood of the vehicle rolling over when cornering or cutting a bend.

[0004] Another advantage of lowering the ride height is increased driving comfort. Many drivers prefer the reduced body roll of a lower ride height. Furthermore, lowering the ride height improves a vehicle's stability when exposed to crosswinds. Many also believe that a lower ride height enhances a vehicle's aesthetics.

[0005] State-of-the-art systems are designed to automatically lower a vehicle's ride height when the vehicle speed exceeds a predefined value. This is known in engineering as "adaptive suspension." Mercedes-Benz uses an example called "Active Body Control" (ABC). ABC lowers a vehicle's ride height by up to 11 mm at speeds above 60 km / h.

[0006] DE 10 2004 060 467 A1 relates to a method for controlling and / or regulating chassis settings in a motor vehicle, in which, depending on the driving situation and / or the road characteristics, the body distance to the vehicle axles is adjusted by means of a leveling device, rolling movements of the body around its longitudinal axis are adjusted by means of a roll stabilization device and / or the damping force of chassis dampers is adjusted by means of a damping force adjustment device.

[0007] DE 38 78 158 T2 relates generally to a device for controlling the suspension of a vehicle, which can suppress roll, front pitch, rear dip and vertical movements, such as pitching and heaving oscillations of a vehicle, in order to enable a more comfortable ride.

[0008] However, lowering the ride height is not always desirable, as it can negatively impact driving dynamics. Lowering a vehicle's ride height reduces its roll center height, resulting in a shift in the vehicle's kinematic roll center. In a lowered configuration, the vehicle frame is closer to the auxiliary springs and further away from the rebound springs. Consequently, in a lowered configuration, the vehicle occupies a more non-linear section of the wheel speed curves, which negatively affects the driving experience.

[0009] When a vehicle with lowered suspension is driven in a dynamic driving environment that requires significant and frequent changes in speed and direction, such as on a winding country road, the vehicle's dynamics will be affected. Steering feel will be impaired, and the required steering effort may change. Furthermore, the linearity of the steering response may be compromised. The linearity of balanced vehicle handling under lateral acceleration may be affected due to the change in height relative to the auxiliary spring contacts. This change in height relative to the auxiliary spring contacts typically reduces ride comfort. In short, a vehicle is optimized to be driven at a standard ride height; any deviation from the standard ride height is detrimental to the driving experience.

[0010] “Full-spirited driving” and “dynamic driving” are terms used in engineering to describe a driving style in which the direction and / or speed of a vehicle is regularly and sometimes abruptly adjusted in dynamic driving environments.

[0011] The international patent application, publication no. WO 2013 / 004 764 A1, describes a system and method for controlling subsystems of a vehicle by evaluating the driving style of the driver of a vehicle.

[0012] The present invention was designed to mitigate or eliminate the aforementioned problems and to take into account disadvantages associated with the prior art. BRIEF SUMMARY OF THE INVENTION

[0013] The aforementioned objectives are at least partially achieved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims, and the person skilled in the art will find further indications of suitable aspects of the present invention in the overall disclosure of the present application.

[0014] According to one aspect of the present invention, a system for determining how a vehicle is driven is provided. The system may include a processor comprising an input configured to receive dynamic driving data from at least one onboard vehicle dynamic driving sensor. The processor may be configured to (i) calculate an output signal indicating whether the dynamic driving data exceeds at least one dynamic driving data threshold for a predetermined period, and (ii) compare the output signal with at least one output threshold to determine how the vehicle is driven. The processor may include an output configured to send a control signal. The control signal may be sent to one or more vehicle components, which may be or include a vehicle suspension system.The control signal can block the vehicle's ride height from being adjusted. The control signal can block the vehicle's ride height from being lowered. The control signal can restrict or limit the vehicle's ride height to a raised configuration. The control signal can indicate how the vehicle is driven.

[0015] The invention enables a quick and efficient determination of how the vehicle is driven, thereby allowing the control signal to be sent to the vehicle components. If the invention determines that the vehicle is being driven dynamically, it can prevent adjustments to the vehicle's ride height, thus mitigating any impairment of the vehicle's dynamics during dynamic driving.

[0016] For example, if the invention detects that the vehicle is being driven dynamically, the control signal can be sent to the vehicle's suspension system or its components, which raise the vehicle's ride height or receive a command to raise it if it is in a lowered configuration, or which maintain the raised configuration or receive a command to maintain it if the suspension components are already in that configuration. Maintaining the raised configuration or receiving a command to maintain it can include the vehicle's suspension system or its components blocking the vehicle's ride height from being lowered or receiving a command to block or limit it. The vehicle's suspension components can include one or more springs, shock absorbers, control devices, and suspension linkages.

[0017] The exceeding of at least one dynamic data threshold event by the dynamic driving data can indicate that the vehicle is being driven dynamically and can be referred to as a dynamic driving event. The exceeding of at least one threshold for dynamic driving data by the dynamic driving data in one or more instances can cause the output signal to exceed the output threshold. For example, a plurality of closely related dynamic driving events can cause the output signal to exceed the output threshold. The invention is further advantageous in that it detects dynamic driving events with high accuracy and determines whether dynamic driving is taking place.

[0018] The processor can be configured to apply a gain value to the output signal if the dynamic driving data exceeds at least one threshold value for dynamic driving data for a specified period. The processor can include a gain module configured to apply the gain value to the output signal.

[0019] Preferably, the processor has at least one exponentially weighted moving average filter configured to calculate a moving average of the dynamic driving data at predetermined intervals and to assign exponential weights to the calculated moving averages in order to calculate the output signal.

[0020] The exponentially weighted moving average filter can take a sample of dynamic driving data over a predetermined period, which can be used to calculate the moving average of the dynamic driving data. The invention can assign a weight to the dynamic driving data such that more recent data has a higher weight than less recent data.

[0021] In an optional embodiment, the specified time period can be five seconds. In another optional embodiment, the specified interval can be five milliseconds (5 ms). Optionally, the moving average of the dynamic driving data can be calculated for each specified interval.

[0022] The at least one output threshold can include an ON / OFF threshold. Any output signal value above the corresponding ON / OFF threshold can indicate dynamic driving. Any output signal value below the corresponding ON / OFF threshold can indicate non-dynamic driving. The processor can determine that lowering the vehicle's ride height should be blocked if the output signal exceeds the corresponding ON / OFF threshold.

[0023] The at least one output threshold can include an ON threshold, whereby a temporary increase in the output signal from below the corresponding ON threshold to above the corresponding ON threshold can indicate dynamic driving. The at least one output threshold can also include an OFF threshold. The OFF threshold can be lower than the corresponding ON threshold. A temporary decrease in the output signal from above the corresponding OFF threshold to below the corresponding OFF threshold can indicate non-dynamic driving.

[0024] The system may include a memory device. The memory device may be configured to store at least one threshold value for dynamic driving data for the sensor(s) for driving attributes. The processor may be configured to access the memory device and execute instructions stored therein, so that it can be operated to calculate the output signal to determine whether the vehicle is being driven dynamically or non-dynamically, and to block the lowering of the vehicle's ride height if it is determined that the vehicle is being driven dynamically.

[0025] The processor can include an electronic processor that has an electrical input for receiving dynamic driving data. The storage device can include an electronic data storage device that is electrically coupled to the electronic processor and in which instructions are stored.

[0026] The control signal can be, or include, a Boolean operator. The system can include a module for converting the output signal into the Boolean operator. The Boolean operator can indicate whether the output signal exceeds at least one output threshold. This indicator can show whether the vehicle is being driven dynamically or non-dynamically. The control signal can be an analog signal that specifies the degree of dynamic driving, which may exceed one or more of the at least one output threshold.

[0027] The input can be configured to receive vehicle speed data from a vehicle speed sensor. The processor can be configured to determine at least one dynamic driving data threshold for the detected vehicle speed data. The processor can be configured to determine whether the vehicle speed exceeds a speed threshold. The processor can be configured to send the control signal only if the vehicle speed is higher than a speed threshold.

[0028] The processor can include at least one absolute value calculator configured to calculate the absolute value of the dynamic driving data. The absolute value is the order of magnitude of the dynamic driving data, regardless of the direction of the forces to which the vehicle is subjected or whether the dynamic driving data is positive or negative. The dynamic driving data can include a measure of the vehicle's lateral acceleration. The dynamic driving data can be received from at least one sensor in an inertial management unit.

[0029] The at least one onboard vehicle dynamics sensor can include an inertial management unit. Dynamic driving data can be received from at least one onboard vehicle sensor for driving attributes. The vehicle's ride height can be configurable between at least two vehicle ride height positions. The processor can be configured to compare the output signal with the corresponding output signal threshold to determine whether lowering the vehicle's ride height to at least one lowered vehicle ride height position should be blocked.

[0030] In an optional embodiment, when the vehicle's ride height has been lowered to a lowered position, the processor can be configured to send a control signal to raise the ride height to a raised position when it is determined that the vehicle will be driven dynamically.

[0031] According to another aspect of the present invention, a method for determining how a vehicle is driven is provided. The method can include receiving dynamic driving data from at least one onboard vehicle dynamic driving sensor. The method can further include processing the dynamic driving data to generate an output signal indicating whether the dynamic driving data exceeds at least one dynamic driving data threshold for a predetermined period. The method can further include comparing the output signal with at least one output threshold to determine how the vehicle is driven. The method can include generating a control signal indicating how the vehicle is driven. The control signal can be sent to block adjustments to the vehicle's ride height.The control signal can block the vehicle's ride height from being lowered. The control signal can restrict or limit the vehicle's ride height to a raised configuration.

[0032] The processing step can include comparing the dynamic driving data with at least one dynamic driving data threshold. The procedure can include amplifying the output signal if the duration of the dynamic driving data remains above the at least one dynamic driving data threshold for a specified period.

[0033] The output signal can decay according to an exponentially weighted moving average filter applied to the dynamic driving data.

[0034] The method may include detecting the vehicle speed. The method may include determining a threshold for dynamic driving data based on the detected vehicle speed. The method may include determining whether the vehicle is being driven dynamically or non-dynamically. The method may include sending the control signal to one or more vehicle suspension components depending on the determination of whether the vehicle is being driven dynamically or non-dynamically. If it is determined that the vehicle is being driven dynamically, the method may include blocking the vehicle's ride height from being lowered.

[0035] According to a further aspect of the present invention, a non-volatile, computer-readable storage medium is provided. This storage medium can store instructions which, when executed by one or more processors, cause the one or more processors to execute the aforementioned method.

[0036] According to another aspect of the present invention, a vehicle is provided which includes a system described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] One or more embodiments of the invention will now be described exclusively by way of example with reference to the accompanying drawings, wherein: Fig. 1(a) shows a schematic top view of a vehicle including a vehicle suspension system (VSS) according to an embodiment of the present invention, wherein the vehicle also includes on-board sensors and suspension components, Fig. 1(b) a side view of the in Fig. 1 shows the vehicle in a raised position, Fig. 1(c) a side view of the in Fig. Figure 1 shows the vehicle in a lowered position. Fig. 2 the components of the in Fig. The VSS shown in point 1, together with the inputs to and outputs from the VSS, shows, Fig. 3 a vehicle kinetic dynamics (VKD) component of the VSS made of Fig. 2 shows in more detail, Fig. 4 shows a procedure that is initiated by the VKD Fig. 3 is executed to determine whether the vehicle is operated dynamically, Fig. 5(a) a graph of lateral acceleration data versus time for part of a vehicle's journey, wherein the lateral acceleration data are based on measurements by at least one on-board sensor Fig. 1 based, Fig. 5(b) the determination shows whether the vehicle is based on the in Fig. 5(a) the data shown is driven dynamically, and Fig. 6 from the VSS Fig. The procedure described in Figure 2 shows how to determine whether the vehicle's ride height can be adjusted from the Fig. 1(a), Fig. 1(b) and Fig. 1(c) should be adapted. DETAILED DESCRIPTION

[0038] In one embodiment of the present invention, a system determines how a vehicle is driven. This determination, together with the vehicle speed, serves to determine whether the vehicle's ride height should be raised, lowered, maintained, or whether the adaptive suspension should be locked.

[0039] Fig. Figure 1(a) shows a top view of a vehicle 10 comprising a vehicle body 12 and four wheels 14. The vehicle 10 also includes one or more onboard vehicle sensors 16a, 16b, an adaptive vehicle suspension system (VSS) 18 according to an embodiment of the present invention, and adaptive vehicle suspension components 20. The suspension components 20 include one or more components that connect the wheels 14 to the rest of the vehicle 10 to cause the vehicle's ride height to be raised or lowered. These components 20 may include springs, shock absorbers, control devices, and suspension linkages.

[0040] The Fig. 1(b) and Fig. Figure 1(c) shows side views of the vehicle 10 in 'raised' and 'lowered' positions 22 and 24, respectively. In the raised position 22, the chassis 26 of the vehicle body 12 is arranged at a first distance D1 from the surface 28 over which the vehicle 10 travels. In the lowered position 24, the chassis 26 of the vehicle body 12 is arranged at a second distance D2 from the surface 28, where D2 is smaller than D1. Typically, the difference between D1 and D2 can be between 5 mm and 50 mm, and more specifically, approximately 15 mm, although the difference can be any other suitable value.

[0041] The VSS 18 can cause the vehicle body 12, relative to the wheels 14, to be raised or lowered between the ride height positions 22 and 24 by sending control signals to the suspension components 20. For example, to adjust the ride height of the vehicle 10 between the raised and lowered positions 22 and 24, the VSS 18 can change the air volume of a suspension component of the air compressor (in an air-sprung vehicle).

[0042] Fig. Figure 2 shows the VSS 18 in more detail. The VSS 18 includes a processor 30 for determining whether the ride height of the vehicle 10 should be adjusted between the raised and lowered positions 22, 24. The processor 30 includes a vehicle kinetic dynamics (VKD) module 32. The VKD 32 is used to determine whether the vehicle is being driven dynamically in a dynamic driving environment or non-dynamically in a calm driving environment. The result of this determination is used by the processor 30 to determine whether an adjustment of the ride height is necessary.

[0043] The data processor 30 has an input 36 which is arranged and configured to receive dynamic driving data from the onboard sensors 16a, 16b. In particular, the processor 30 receives dynamic driving data 50a, which is used by the VKD 32 to determine how the vehicle 10 is driven. In the embodiment described herein, dynamic driving data 50a includes signals relating to the lateral and longitudinal acceleration acting on the vehicle 10. Lateral and longitudinal acceleration are known in the art as lateral and longitudinal acceleration forces. The onboard sensors 16a, 16b can include onboard vehicle dynamics sensors, such as lateral acceleration sensors, or one or more inertial measurement units (IMUs), including accelerometers.

[0044] In further embodiments of the invention, the onboard sensors 16a, 16b can include: separate sensors for vehicle roll rate, vehicle pitch rate, and vehicle heave acceleration (i.e., vertical acceleration), or the roll, pitch, and heave data can be received by a single inertial measurement unit (IMU) including a three-dimensional accelerometer. Alternatively or in combination, the onboard sensors 16a, 16b can measure driver-induced roll as a measure of spirited driving. Furthermore, the onboard sensors 16a, 16b can include sensors to provide measurements of any combination of engine speed, steering wheel angle, steering wheel rotation speed, yaw rate, wheel speed, wheel height above a wheel, longitudinal acceleration, and throttle position.These additional sensors and measurements provide further dynamic driving data 50a, which can be processed in further embodiments of the invention.

[0045] The processor 30 also receives vehicle speed data 50b, which is used to determine whether a ride height adjustment is appropriate. The vehicle speed data 50b is obtained from a speed sensor 16b. In short, lowering the ride height is generally only suitable if the vehicle speed exceeds a certain threshold. This is explained in more detail below.

[0046] The VSS 18 includes a data storage device 34 in which instructions are stored, and the data processor 30 is configured to execute these instructions to determine how the vehicle is driven and whether the ride height should be adjusted. The data storage device 34 can be an electronic, non-volatile, computer-readable storage medium. The data storage device 34 also includes predefined vehicle driving attribute data, such as at least one dynamic driving data threshold, and predefined vehicle speed reduction data, which are used by the processor 30 to execute the foregoing instructions.

[0047] The processor 30 has an output 38 configured to send a control signal 127 to the suspension components 20. The control signal 127 indicates how the vehicle is being driven. Accordingly, if the control signal 127 indicates dynamic driving, upon receipt of the control signal 127, the adjustment of the vehicle's ride height 10 is blocked, so that the suspension components 20 do not switch the vehicle's ride height from the raised position 22 to the lowered position 24. If the vehicle's ride height 10 is in the lowered position 24 after receiving the control signal 127, the ride height is adjusted to the raised position 22. This is described in more detail below.

[0048] Fig. Figure 3 shows the structure of the VKD 32 in detail. The VKD 32 receives lateral acceleration (latacc) signals 50a via the lateral acceleration sensor 16a, and vehicle speed signals 50b via the speed sensor 16b. The lateral acceleration signals 50a and the vehicle speed signals 50b are processed in parallel.

[0049] The lateral acceleration signals 50a can contain positive and negative values, corresponding to the lateral acceleration of the vehicle 10 in the left and right directions. To analyze the signal, the absolute value of each lateral acceleration value, i.e., the order of magnitude of each lateral acceleration value regardless of its direction, is determined and output by an absolute value calculator 44. The absolute latacc value is passed on to an exponentially weighted moving average filter 46 and a state flow diagram 42.

[0050] The exponentially weighted moving average filter 46 ensures that the lateral acceleration signals 50a, most recently received by the processor 30, are given greater weight in the dynamic driving analysis. This allows the VKD 32 to react more quickly to changes in driving dynamics and improves the consistency of the driving dynamics determination. Specifically, the average of the most recently processed n signal values ​​is calculated. Then, the oldest values ​​are discarded and replaced by newly received values ​​a, where a < n, and the new average is calculated. This process is repeated, and the calculated averages are called moving averages. These calculated moving averages are weighted, with the weights decreasing exponentially towards the averages associated with the older received signals.

[0051] The exponentially weighted moving average filter 46 receives inputs of the processed lateral acceleration signals 50a from the absolute value calculator 44 and the moving average sample size from the moving average filter module 66 (i.e., the value n). The moving averages are calculated at predefined intervals. For example, if the predefined interval is 5 ms, the moving average is calculated every 5 ms. The number of samples averaged is defined over time. In the present embodiment of the invention, the interval is five seconds, but it can be calibrated to a different time period. Accordingly, the number of samples averaged every 5 ms in the present embodiment of the invention is one thousand. The calculated averages are then output by the filter 46.

[0052] Referring to the vehicle speed signals 50b, each vehicle speed signal 50b is forwarded to a first comparison module 52a and a second comparison module 52b. The first comparison module 52a compares the vehicle speed signal 50b with an OFF threshold provided by a first OFF threshold module 54a. The OFF threshold is the speed at which the adaptive suspension is not locked. The second comparison module 52b compares the vehicle speed signal 50b with an ON threshold module 54b. The ON threshold is the speed at which the adaptive suspension is locked.

[0053] The results of the OFF and ON threshold modules 54a and 54b are passed to their respective addition modules 56a and 56b. Each addition module 56a and 56b combines the result of its respective OFF or ON threshold module 54a and 54b with an offset threshold provided by the offset threshold modules 58a and 58b. The result of the first addition module 56a provides the signal with respect to the threshold for switching off the adaptive suspension; and the result of the second addition module 56b provides the signal with respect to the threshold for switching on the adaptive suspension.

[0054] The output of the comparison modules 52a, 52b and the addition modules 56a, 56b each form a linear equation y = mx + c, where m represents the gradient of the line and c the offset. The gradients m are defined by the OFF and ON threshold modules 54a, 54b, and the offsets c are defined by the offset threshold modules 58a, 58b. The lines then form the threshold equation, where x represents the vehicle speed and y the lateral acceleration. The resulting line is a graphical representation of the lateral acceleration threshold versus the speed. A lateral acceleration event that exceeds the lateral acceleration threshold for a given speed indicates a dynamic driving event.

[0055] In addition to receiving the absolute latacc value from the absolute value calculator 44, the state flow diagram 42 receives (i) a signal from the OFF threshold addition module 56a; (ii) a signal from the ON threshold addition module 56b; (iii) a gain value from a gain module 60; (vi) an output signal threshold and a predefined time value for the ON threshold from the output signal threshold module 62; and (v) the sampling frequency of the velocity and absolute latacc values ​​from the module 64.

[0056] The state flow diagram 42 processes its inputs to determine whether the vehicle 10 is being driven dynamically. In this respect, the state flow diagram 42 monitors the absolute latacc value from the absolute value calculator 44 and, in particular, how long the lateral acceleration remains above the ON threshold specified by the ON threshold module 54b.

[0057] The result of the analysis of the state flow diagram 42 is passed to a third addition module 56c, which combines the result of the state flow diagram 42 with the output of a step delay module 68. The result of the third addition module 56c is passed to the weighted moving average filter 46. The weighted moving average filter 46 also receives a sample size from the moving average filter module 66.

[0058] If the lateral acceleration exceeds the ON threshold for the specified time value for the ON threshold, the gain value provided by the gain module 60 is added to the weighted moving average signal for the lateral acceleration, i.e., the signal output of the exponentially weighted moving average filter 46.

[0059] The result of the weighted moving average filter 46 is forwarded to module 70. The output of module 70 calculates an output signal 125, which indicates whether the lateral acceleration exceeds the ON threshold for the specified time value. The output signal 125 can be monitored by an external device 72a. Module 70 forwards its results to the sampling rate module 68 and the relay block 48.

[0060] Relay block 48 forwards the output signal 125, associated with the lateral acceleration of the vehicle 10, to a Boolean converter 49. The output signal 125 is compared with a preconfigured threshold to determine how the vehicle 10 is driven. If the output signal 125 exceeds the preconfigured threshold, the Boolean converter 49 converts the output signal 125 into a Boolean operator, which is a control signal 127 in the form of a spirited driving flag indicating whether the vehicle is being driven dynamically or non-dynamically. The output of the Boolean converter 49 is monitored by an external device 72b.

[0061] In an alternative embodiment of the invention, the output signal 125 can be passed through an analog converter (not shown) which generates an analog control signal (not shown) that indicates the degree of dynamic driving to which the vehicle 10 is subjected.

[0062] In the present embodiment of the invention, the external device 72b represents the suspension components 20. Upon receiving a Boolean operator indicating that the vehicle is being driven dynamically, i.e., the spirited driving flag is set to ON, the suspension components 20 block the lowering of the adaptive suspension. Alternatively, upon receiving a Boolean operator indicating that the vehicle is being driven non-dynamically, i.e., the spirited driving flag is set to OFF, the suspension components 20 do not block the lowering of the adaptive suspension.

[0063] Fig. Figure 4 illustrates a method 100 for determining how a vehicle 10 is driven. The method 100 is executed by the VKD 32 to determine whether the vehicle 10 is driven dynamically. The method begins at step 101. At step 102, the VKD 32 of the processor 30 receives dynamic driving data 50a, which includes the measured lateral acceleration of the vehicle 10 from at least one onboard vehicle dynamic driving sensor 16a. In the embodiment described here, the at least one onboard vehicle dynamic driving sensor 16a is the lateral acceleration sensor 16a, which generates dynamic driving data 50a in the form of one or more lateral acceleration signals. At step 104, the VKD 32 of the processor 30 receives the measured vehicle speed from the speed sensor 16b. Typically, the sampling frequency of these signals can be 200 Hz, but any other suitable value can be used, such as 100 Hz.

[0064] In step 106, the VKD 32 determines the lateral acceleration threshold for the speed detected by the speed sensor 16b. If the dynamic driving data 50a, which in the embodiment described here represents the lateral acceleration of the vehicle from step 102, exceeds at least one dynamic driving data threshold, which in the current embodiment represents the lateral acceleration threshold, the state flow diagram 42 determines in step 108 the time period during which the lateral acceleration threshold was above the threshold. If the time period exceeds a predefined time period stored in the output signal threshold module 62, a calibratable gain value is applied to the output signal in step 110 by the value stored in the gain module 60.

[0065] As stated above, the moving average filter 46 averages the lateral acceleration (latacc) signals 50a received from the lateral acceleration sensor 16a. If the vehicle's lateral acceleration from step 102 exceeds the lateral acceleration threshold, the exponentially weighted moving average filter in step 112 is applied to the lateral acceleration signal by the weighted moving average filter 46.

[0066] In step 114, the state flow diagram 42 combines the result of the exponentially weighted moving average filter assigned in step 112, and the gain value is applied to the output signal in step 110. In step 116, the output signal is compared by the state flow diagram 42 to at least one output threshold to determine whether the threshold has been violated, thus determining how the vehicle 10 is being driven. If the threshold has been violated, the car is assumed to be driven dynamically, i.e., spirited driving is detected, as shown in step 118. Accordingly, the output signal 125 indicates whether the dynamic driving data exceeds the at least one dynamic driving data threshold for a predetermined time period. If the threshold has not been violated, the procedure 100 restarts from the beginning, i.e., in step 101.

[0067] The Fig. 5(a) and Fig. 5(b) illustrate the above-mentioned procedure in graphical form. Fig. Figure 5(a) shows a graph 120 for lateral acceleration data signals 50a, versus time for a portion of the vehicle 10's journey. The y-axis 122 indicates the order of magnitude of an absolute raw lateral acceleration signal 50a. The curve of graph 120 indicates the order of magnitude of the lateral acceleration signal 50a at the time in seconds along the x-axis 121 of the lateral acceleration graph 120.

[0068] Fig. Figure 5(b) shows a graph 124 of the output signal 125 of the state-flow diagram 42, against the time for the movement of the in Fig. 5(a) of the vehicle 10 shown. The y-axis 126 shows the output signal of the state flow diagram 42 at the times specified by the x-axis 121 of the output graph 124.

[0069] The in Fig. Graph 122 shown in Figure 5(a) for lateral acceleration illustrates that the vehicle 10 is subjected to a relatively small lateral acceleration, i.e., an absolute raw signal strength between zero and two, until approximately 28 seconds. After 28 seconds, the signal strength rapidly increases to approximately four, fluctuates between approximately 3.8 and 5.4 for about 4 seconds, and then rapidly drops to zero at approximately 35 seconds.

[0070] In the present embodiment of the invention, the EIN threshold for lateral acceleration is set to 3.8 ms². -2(set at 96 kph). The lateral acceleration raw signal 50a exceeds the ON threshold for between approximately 28 and 35 seconds, indicating that the vehicle 10 is subjected to high lateral acceleration. The duration for which the lateral acceleration raw signal 50a exceeds the ON threshold is longer than the preset time stored in the gain module 60; a single dynamic driving event is detected. As stated above, the threshold changes with respect to the vehicle speed.

[0071] Graph 124 of the in Fig. The output signal 125 shown in Figure 5(b) indicates that the gain by the gain module 60 is applied to the output signal shortly after 30 seconds have elapsed since the start of the analysis. At this point, the output signal 125 is boosted from zero to five. The output signal 125 is held at five for 2 to 3 seconds during the dynamic driving process before decaying. The decay rate depends on the exponentially weighted moving average of the absolute lateral acceleration value averaged over five seconds. Since the gain is applied shortly after 30 seconds, the average absolute lateral acceleration was low. Therefore, the decay rate is low.

[0072] Before further amplification can be applied to the raw signal 50a, the raw signal 50a must fall below an OFF threshold value, which in this embodiment is 1.5 ms -2The raw signal 50a rises rapidly from zero to approximately 6.2 at 36 seconds before gain can be applied again to the output signal 125. This rise is necessary to either fall below or exceed the ON threshold. Another gain is applied to the output signal 125 at 38 seconds to raise it to ten. The raw signal 50a falls to zero at 46 seconds before rapidly rising to approximately 6.3 at approximately 47 seconds. Consequently, a third gain is applied to the output signal 50a at approximately 47 seconds, raising it to 14.

[0073] In the embodiment described here, a number of spirited driving events occur within a specific timeframe before the system considers the vehicle 10 to be driven dynamically. In this embodiment of the invention, the threshold for dynamic driving is set to ten. As stated above, upon the third detection of dynamic driving, the output signal is raised to ten and the spirited driving flag is triggered to be set to ON, i.e., the Boolean output of the Boolean converter 49 is set to 1.

[0074] An ON state blocks the vehicle's ride height from being lowered, or, if the vehicle's ride height is already in the lowered position, the ON state causes the vehicle's ride height to be raised to the normal ride height. The spirited driving flag is indicated by an output line of a Boolean function that switches from zero to 1 when the averaged lateral acceleration signal, amplified by individual spirited driving events, exceeds a preconfigured threshold of 128. Fig. 5(b) the preconfigured threshold is 10. In the Fig. 5(a) and Fig. In the example shown in 5(b), the individual spirited driving event, which takes place at approximately 46 seconds, causes the amplified output signal 125 to exceed the value 10, thus setting the output of the Boolean function to 1.

[0075] From approximately 47 seconds until the end of the curve of signal 50a on graph 120 for lateral acceleration, the raw signal 50a rapidly alternates between zero and raw signals 50a corresponding to relatively high lateral acceleration forces. These rapid and significant changes in raw signal 50a are reflected in output signal 125, which is amplified each time a dynamic driving event is detected. Output signal 125 decays to a weighted moving average. The longer the time frame over which the average is calculated, the less the decay rate reacts to the raw lateral acceleration signal 50a. As an expert will understand, a high average raw signal 50a results in a low decay rate of output signal 125, and conversely, a low average raw signal 50a results in a high decay rate of output signal 125.The output signal 125 is limited to twenty to prevent it from being continuously amplified, thus preventing it from taking an excessively long time to fall below the OFF threshold of relay block 48. If the output signal 125 is not limited, the vehicle's suspension 10 may remain in the raised configuration long after the end of the dynamic driving events.

[0076] The OFF threshold is not equal to its corresponding ON threshold to prevent any of the moving average values ​​from fluctuating between the display of dynamic driving and non-dynamic driving. This can be described as signal hysteresis. Such fluctuations could cause the vehicle's ride height 10 to be raised and lowered several times within a short period, which is entirely undesirable. This also takes into account that there is a slight delay in the movement between the raised and lowered positions 22, 24; that is, it is a responsive system to maintain ride comfort.

[0077] The ON and OFF thresholds are calibrated before the system is deployed. These thresholds are based on a level of impairment to the vehicle's driving dynamics that is deemed "acceptable" by a subjective expert. For example, the ON and OFF thresholds are calibrated to minimize any impairment.

[0078] The overall determination performed by the VKD 32 as to whether the vehicle 10 is being driven dynamically is then used by the processor 30 to determine whether the lowering of the adaptive suspension should be blocked. In some embodiments, the determination that the vehicle is being driven dynamically can also lead to the adjustment of the vehicle's ride height, i.e., the vehicle's ride height is raised if the vehicle 10 is in the lowered configuration.

[0079] Fig. Figure 6 shows a procedure 200, executed by processor 30, to determine whether the lowering of the adaptive suspension should be blocked. The procedure 200 begins in step 201 with the vehicle 10 in its raised position 22.

[0080] In step 202, the processor 30 determines whether the conditions for locking the adaptive suspension are met. Specifically, the processor 30 receives the vehicle speed data 50b, which is obtained from a speed sensor 16b. The processor 30 also retrieves a predefined threshold value for the vehicle speed, which is stored in the data memory 34. Specifically in step 202, the processor 30 determines whether the vehicle speed is greater or less than the predefined threshold speed for triggering the locking of the adaptive suspension.

[0081] If the vehicle speed is lower than the specified threshold speed, then the conditions for locking the adaptive suspension are not met. Accordingly, the adaptive suspension is not locked and the process returns to step 201.

[0082] If the vehicle speed is greater than the specified threshold speed, the conditions for blocking the adjustment of the vehicle's ride height 10 are met, and procedure 200 proceeds to step 204.

[0083] In step 204, the processor 30 determines whether the vehicle 10 is being driven dynamically, i.e., whether the vehicle is subjected to spirited driving. In particular, the VKD 32 of the processor 30 determines whether the vehicle 10 is being driven according to the procedure 100 described above. Fig.4 is driven dynamically. The control signal 127 is sent to the suspension components 20, with the control signal 127 indicating how the vehicle 10 is driven.

[0084] Specifically, when the spirited driving flag is set to ON, it is determined that the vehicle 10 is being driven dynamically, so the adaptive suspension should be locked. Accordingly, the ride height of the vehicle 10 is locked by preventing it from moving from the raised position 22 to the lowered position 24. If the ride height of the vehicle 10 is in the lowered position 24 when the spirited driving flag is set to ON, the adaptive suspension reconfigures the ride height to the raised position 22 and prevents it from moving back to the lowered position 24 while the vehicle 10 is being driven dynamically. When the vehicle 10 is subjected to spirited driving, the process returns to step 202.

[0085] Alternatively, if it is determined that the vehicle 10 is not driven dynamically, then the VSS 18 outputs an alternative control signal (not shown) to the suspension components 20 in step 206. The alternative control signal (not shown) does not block the adaptive suspension. Accordingly, the adaptive suspension can be active and control the ride height of the vehicle 10 in the usual way. Therefore, adjusting the ride height of the vehicle 10 is not blocked if the vehicle 10 is not driven dynamically.

[0086] Vehicle 10 then remains in the lowered position 24 until it is determined that the ride height should be raised to the raised position 22. In particular, in step 208, processor 30 checks whether vehicle 10 is being driven dynamically in a manner similar to that described above.

[0087] If it is still determined that the vehicle is being driven non-dynamically, the processor 30 does not send a control signal 127 to block the adaptive suspension and loops back to step 208 in step 210. However, if it is determined that the vehicle 10 is being driven dynamically, the VSS 18 outputs a control signal 127 to the suspension components 20 in step 212 to raise the ride height of the vehicle 10 from the lowered position 24 to the raised position 22 and to block further operation of the adaptive suspension.

[0088] In the embodiment described above, the vehicle 10 has two ride height positions, i.e., the raised and lowered positions 22, 24. However, in other embodiments, the vehicle may have more than two ride height positions. In these embodiments, the system can determine the degree of dynamic driving based on the degree of lateral acceleration. For example, the system can control the suspension components 20 to adjust the ride height to one of three or more positions based on the determined degree of dynamic driving.

[0089] Many changes can be made to the preceding examples without deviating from the scope of the present invention as defined in the accompanying claims.

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