CONTROL OF THE LATERAL DYNAMIC BEHAVIOR OF A VEHICLE

Abstract

A vehicle includes suspension components, including shock absorbers. The shock absorbers are controlled by a control system that receives two or more input signals relating to the lateral roll of the vehicle body and normalizes these signals to produce two or more normalized signals. These normalized signals are combined, and the combined signal, along with the vehicle's speed, is used to calculate a common damping force. This common damping force is then used to calculate a damping force appropriate to each wheel of any multiple wheels on the vehicle. The operation of a shock absorber for a given wheel is then determined by the damping force corresponding to that wheel.The two or more input signals relating to the lateral tilt of the vehicle body can include steering speed, lateral acceleration, lateral jerk, and yaw rate.

Description

INTRODUCTION

[0001] This application claims the benefit of the preliminary US patent application with serial number 63 / 682,747, filed on August 13, 2024, entitled CONTROLLING LATERAL DYNAMICS OF A VEHICLE. INTRODUCTION

[0002] The present disclosure relates to controlling the lateral dynamic behavior of a vehicle. SUMMARY

[0003] In one aspect, a control system for use in a vehicle is configured to receive two or more input signals relating to the lateral tilt of the vehicle body, combine the two or more input signals to obtain a combined signal, and calculate a common damping force based on the combined signal and the vehicle's speed. The control system processes the common damping force to calculate a damping force corresponding to each wheel of any multiple wheels on the vehicle. The control system is configured to dictate the operation of a damper corresponding to each wheel of the multiple wheels on the vehicle, depending on the damping force corresponding to each wheel.

[0004] According to another aspect, a vehicle includes a chassis, a multitude of wheels, and a multitude of suspensions connecting the multitude of wheels to the chassis, each suspension of the multitude including a damper. The vehicle includes a control system configured to receive two or more input signals relating to the lateral roll of the vehicle body, to normalize the two or more input signals to obtain two or more normalized signals, and to combine the two or more normalized signals to obtain a combined signal. The control system calculates a common damping force based on the combined signal and the vehicle's speed. The control system processes the common damping force to calculate a damping force appropriate to each wheel of the multitude of wheels of the vehicle.The control system dictates the operation of a vehicle damper, corresponding to each of the vehicle's multiple wheels, depending on the damping force corresponding to each wheel.

[0005] According to another aspect, a damper control method involves a vehicle's control system receiving two or more input signals relating to the lateral roll of the vehicle body and normalizing these two or more input signals to obtain two or more normalized signals. The control system combines these two or more normalized signals to obtain a combined signal and calculates a common damping force based on this combined signal and the vehicle's speed. The control system then processes this common damping force to calculate a damping force corresponding to each wheel of the vehicle's multitude of wheels. The control system dictates the operation of each of the vehicle's dampers, corresponding to each wheel of the vehicle's multitude, based on the damping force assigned to each wheel. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1A illustrates an exemplary vehicle that can be operated according to certain embodiments. Fig. Figure 1B illustrates a vehicle chassis with multiple drive units that can be operated according to certain embodiments. Fig. Figure 2 is a schematic block diagram of components for operating the vehicle according to certain embodiments. Fig. 3A is a schematic block diagram that defines forces and directions relating to the control of the dynamic behavior of a vehicle. Fig. 3B is a schematic representation illustrating the suspension of a vehicle. Fig. Figure 4 is a schematic block diagram of an approach for controlling dampers of a vehicle according to an embodiment of the present disclosure; Fig. 5A and Fig. Figure 5B are graphical representations of input signals relating to the lateral tilt of the vehicle body, according to an embodiment of the present invention. DETAILED DESCRIPTION

[0006] A vehicle suspension includes springs (e.g., coil, leaf, or air springs) to absorb shocks to the vehicle's wheels, enabling stable handling and enhancing passenger comfort. The suspension also includes dampers to limit the movement of the vehicle chassis relative to the wheels. In particular, dampers can be used to limit body roll (rotation around the vehicle's longitudinal axis). In the approach described here, the force exerted by dampers is controlled by valves that regulate the flow of hydraulic fluid in response to the movement of the wheels relative to the vehicle chassis. The force exerted by a damper is determined based on the driving mode, vehicle speed, and values ​​related to the vehicle's body roll, such as lateral acceleration, steering speed, lateral jerk (rate of change of lateral acceleration), and yaw rate.

[0007] Damper tuning is simplified by normalizing signals related to vehicle body roll and combining them into a single signal. This combined signal is then used to determine a common damping force based on other variables such as vehicle speed and driving mode. The common damping force is then easily processed to determine the damping force to be developed at each individual damper. This approach reduces the number of tunable parameters while still accommodating multiple signals related to vehicle body roll. As a result, suspension tuning is simplified while still achieving the desired dynamic vehicle behavior.

[0008] Fig. Figure 1A illustrates an exemplary vehicle 100 in which the approach described herein can be implemented. As in Fig. As can be seen in Figure 1A, the vehicle 100 has several external cameras 102 and one or more front displays 104. Each of these external cameras 102 can capture a particular view or perspective of the exterior of the vehicle 100. The images or videos captured by the external cameras 102 can then be displayed on one or more displays in the vehicle 100, for example, the one or more front displays 104, for viewing by a driver.

[0009] How Fig. As can be seen from 1B, the vehicle 100 can include a chassis 106 which includes a frame 108 that provides a primary structural element of the vehicle 100. The frame 108 can be formed from one or more struts or other structural elements, or it can be integral with the body of the vehicle (e.g., unibody construction).

[0010] In embodiments where the vehicle 100 is a battery electric vehicle (BEV) or possibly a hybrid vehicle, a large battery 110 is mounted on the chassis 106 and can occupy a considerable area within the frame 108 (e.g., at least 80 percent of it). For example, the battery 110 can store between 100 and 200 kilowatt-hours (kWh). The battery 110 can be a lithium-ion battery or another type of rechargeable battery. The battery can essentially have a planar shape.

[0011] The power of the battery 110 can be supplied to one or more drive units 112. Each drive unit 112 can consist of an electric motor and possibly a gear train that provides a reduction gear. In some embodiments, there is a single drive unit 112 that drives either the front wheels or the rear wheels of the vehicle 100. In another embodiment, there are two drive units 112, each driving either the front wheels or the rear wheels of the vehicle 100. In yet another embodiment, there are four drive units 112, each driving one of the four wheels of the vehicle 100.

[0012] The drive units 112 can be powered by one or more power modules 114 from the battery 110, for example, by one power module for each drive unit 112 or for each pair of drive units 112. The power module 114 can include inverters configured to convert direct current (DC) from the battery 110 into alternating current (AC), which is supplied to the motors of the drive units 112. The power module 114 also enables the motors of the drive units to operate as generators to provide regenerative braking. The power module 114 further enables the transfer of the regenerative power to the battery 110.

[0013] The drive units 112 are connected to two or more hubs 116, to which wheels can be mounted. Each hub 116 includes a corresponding brake 118, such as the illustrated disc brakes. Each hub 116 is further connected to the frame 108 via a suspension 120. The suspension 120 can include metal or air springs for shock absorption. The suspension 120 can be designed as a pneumatic or hydraulic suspension, allowing the ride height of the chassis 106 relative to a support surface to be adjusted. The suspension 120 can include a damper, the damper's characteristics being either fixed or electronically adjustable.

[0014] In the embodiment of Fig. In 1B and in the discussion below, vehicle 100 is a battery-powered electric vehicle. However, a hybrid electric vehicle can also benefit from the approach described herein. Likewise, applications outside of vehicles that use an inverter or other relevant power component can also benefit from the approach described herein.

[0015] Fig. Figure 2 illustrates exemplary components of vehicle 100. Fig. 1A. As in Fig. As shown in Figure 2, the vehicle 100 includes cameras 102, one or more front displays 104, a user interface 200, one or more sensors 202, a motion sensor 204 (e.g., a vehicle speed sensor 204a, an accelerometer 204b, or another type of motion sensor), and a positioning system 206. The one or more sensors 202 may include ultrasonic sensors, radio detection and range sensors (RADAR sensors), light detection and range sensors (LIDAR sensors), or other sensor types. The positioning system 206 may be implemented as a GPS receiver (Global Positioning System receiver). The user interface 200 allows a user, such as a driver or passenger in the vehicle 100, to make inputs.

[0016] The components of the vehicle 100 may include one or more temperature sensors 208. The temperature sensors 208 may include sensors configured to detect ambient air temperature, battery 110 temperature, a power module 114 temperature, each drive unit 112 temperature and / or each motor of each drive unit 112 temperature, the temperature of the coolant entering or leaving a cooling system, the oil temperature in a drive unit 112 temperature, or the temperature of any other component of the vehicle 100. The temperature sensors 208 may include a temperature sensor mounted directly on a microprocessor of the power module 114, as described in more detail below.

[0017] A control system 214 executes instructions to perform at least some of the actions or functions of the vehicle 100. For example, the control system 214, as in Fig. Figure 2 shows one or more electronic control units (ECUs) configured to perform at least some of the actions or functions of the vehicle 100, including those described below. In certain embodiments, each ECU is responsible for a specific group of functions.

[0018] Certain features of the embodiments described herein may be controlled by a telematics control module ECU (TCM-ECU). The TCM-ECU may provide a wireless vehicle communication gateway to support functions such as, but not limited to, over-the-air (OTA) software updates, vehicle-to-the-Internet communication, vehicle-to-a-computer communication, on-board navigation, vehicle-to-vehicle communication, vehicle-to-landscape feature communication (e.g., automated toll road sensors, automated toll plazas, power delivery devices at charging stations), or automated calling functionality.

[0019] Certain features of the embodiments described herein can be controlled by a central gateway module ECU (CGM-ECU). The CGM-ECU can serve as the vehicle's communication hub, connecting and transmitting data to and from the various ECUs, sensors, cameras, microphones, motors, displays, and other vehicle components. The CGM-ECU can include a network switch that provides connectivity via control area network (CAN) ports, local area network (LIN) ports, and Ethernet ports. The CGM-ECU can also act as the master controller over the various vehicle modes (e.g., road mode, park mode, off-road mode, towing mode, camping mode) and thereby control certain vehicle components related to switching the vehicle into one of the vehicle modes.

[0020] In various embodiments, the CGM-ECU collects sensor signals from one or more sensors of the vehicle 100. For example, the CGM-ECU can collect data from cameras 102, sensors 202, the motion sensor 204, the positioning system 206, and temperature sensors 208. The sensor signals acquired by the CGM-ECU are then transmitted to the corresponding ECUs for processing.

[0021] The control system 214 may also include one or more additional ECUs, such as, for example and without limitation: a Vehicle Dynamics Module ECU (VDM ECU), an Experience Management Module ECU (XMM ECU), a Vehicle Access System ECU (VAS ECU), a Near Field Communication ECU (NFC ECU), a Body Control Module ECU (BCM ECU), a Seat Control Module ECU (SCM ECU), a Door Control Module ECU (DCM ECU), a Rear Zone Control ECU (RZC ECU), an Autonomy Control Module ECU (ACM ECU), an Autonomous Safety Module ECU (ASM ECU), a Driver Monitoring System ECU (DMS ECU) and / or a Winch Control Module ECU (WCM ECU).

[0022] If the vehicle 100 is an electric vehicle, one or more ECUs can provide functions related to the vehicle's battery pack, such as a battery management system ECU (BMS-ECU), a battery power isolation ECU (BPI-ECU), a balancing voltage temperature ECU (BVT-ECU), and / or a thermal management module ECU (TMM-ECU). In various configurations, the XMM-ECU transmits data to the TCM-ECU (e.g., via Ethernet, etc.). Additionally or alternatively, the XMM-ECU can transmit other data (e.g., audio data from microphones 216, etc.) to the TCM-ECU.

[0023] With reference to Fig. 3A The dynamic behavior of the chassis 106 relative to the wheels of the vehicle 100 can be understood in terms of the X, Y, and Z directions, all of which are perpendicular to each other. The X direction (also referred to as the longitudinal direction) can be defined as the direction of travel of the vehicle 100 when traveling straight ahead, the Z direction (also referred to as the vertical direction) can be understood as the direction of gravity when the vehicle 100 is on a flat surface. The Y direction (also referred to as the transverse direction) is perpendicular to the X and Y directions.

[0024] The wheels of the vehicle 100 can include a left front wheel 300a, a right front wheel 300b, a left rear wheel 300c, and a right rear wheel 300d. The front wheels 300a and 300b are typically steered, but all-wheel steering is also possible. The movement of the chassis 106 relative to the wheels 300a–300d can include a lateral tilt 302a of the vehicle body (rotation about an axis parallel to the X-direction), a pitching motion 302b (rotation about an axis parallel to the Y-direction), and a yaw motion 302c (rotation about an axis parallel to the Z-direction). The lateral acceleration 304 discussed herein can be defined as acceleration parallel to the Y-direction. The lateral jerk discussed herein can be defined as the first derivative of the lateral acceleration 304.

[0025] The suspension 120 for each wheel 300a-300d can independently control the forces that counteract the movement of the chassis 106 relative to the wheels 300a-300d in two directions, which generally (e.g., within 10 degrees) run parallel to the Z-direction. These forces can include a compression force 310, which counteracts a compression of the suspension 120, e.g., a downward movement of the chassis 106 along the Z-direction relative to the wheels 300a-300d, and a rebound force 312, which counteracts an extension of the suspension 120, e.g., a movement of the chassis 106 upward along the Z-direction relative to the wheels 300a-300d.

[0026] Fig. Figure 3B shows a simplified representation of a suspension 120 for a wheel 300a-300d. The suspension 120 can include a spring inserted between the chassis 106 and a linkage 320, such as a wishbone, that connects the wheel 300a-300d to the chassis 106. The spring can be an air spring 322, allowing the effective spring constant of the air spring 322 to be dynamically changed to adjust the ride height of the vehicle 100 and to compensate for steady-state forces (e.g., low-frequency forces, such as those less than 1 Hz) that cause a lateral roll 302a of the vehicle body. The air spring 322 can be replaced by any other type of spring, such as a coil or leaf spring. The air spring 322 provides a restoring force in response to the forces exerted on the wheel 300a-300d and the inertial forces exerted by the chassis 106.

[0027] The suspension 120 can also include a damper 324, which is connected between the chassis 106 and the linkage 320 and which counteracts movement of the chassis 106 relative to the wheel 300a-300d. The resistance is mainly (e.g., at least 90%) inelastic, for example, due to viscosity losses. The damper 324 can serve to limit vibrations caused by the spring-mass system formed by the chassis 106 and the air spring 322. As explained in more detail below, the damper 324 can also be used to control the degree of lateral roll 302a of the vehicle body during cornering.

[0028] In some embodiments, the damper 324 is configured as a cylinder 326 and a piston 328 sliding within the cylinder 326, or behaves analogously to these. Hydraulic fluid in the cylinder 326 can be forced out of the cylinder 326 through the valves 328a and 328b, which are arranged on both sides of the piston 328. For example, the flow through valve 328a can be induced by the compression of the suspension 120 (the chassis 106 is moved in the direction of the linkage 320) and thus determine the magnitude of the compression force 310 exerted by the damper 324. The flow through the valve 328b can be induced by the rebound of the suspension 120 (the chassis 106 is moved away from the linkage 320) and thus determine the measure of the rebound force 312 exerted by the damper 324.Valves 328a and 328b can be interconnected: the flow exiting valve 328a flows into valve 328b and vice versa. Alternatively, pressure downstream of valves 328a and 328b can be controlled by a hydraulic system 330, which provides a supply of hydraulic fluid and may maintain pressure at valves 328a and 328b.

[0029] Each wheel 300a-300d has a corresponding suspension 120 and components of this suspension (e.g. cylinder 326, valves 328a, 328b, cylinder 326) are herein referred to as corresponding to this wheel 300a-300d or to the wheel 300a-300d corresponding to these components.

[0030] Although the examples here refer to hydraulic dampers, once the damping force has been determined according to the approach described below, it can be achieved using any type of damper known in engineering.

[0031] Fig. Figure 4 illustrates an approach to controlling the valves 328a, 328b of the dampers 324. The approach from Fig. 4 can be implemented using the control system 214, such as one or more ECUs of the control system 214. For example, the vehicle dynamics module (VDM) can be used. The approach in Fig. Figure 4 illustrates components and a corresponding procedure, which is implemented by performing the functions attributed to the components as described below.

[0032] In the approach of Fig. 4. A command stage 400 can generate a valve command 402 for each valve 328a, 328b of each suspension 120. The valve command 402 for a valve 328a, 328b can specify an opening degree of the valve 328a, 328b and the corresponding force (compression force 310 or rebound force 312) exerted by the damper 324 including the valve 328a, 328b.

[0033] The command level 400 can generate the valve command 402 for the valves 328a, 328b corresponding to a wheel 300a-300d, based on a damping force 404 determined for this wheel 300a-300d. Fig. Figure 4 illustrates an approach to determining the damping forces 404 which is based on a large number of input signals and at the same time requires tuning of relatively few parameters to achieve the desired driving behavior of the vehicle.

[0034] The input signals can include the steering speed 406a, e.g., a rate of change of the steering angle of the steered wheels (e.g., the front wheels 300a, 300b), specified by the driver, an autonomous driving algorithm, or a combination thereof. The input signals can include the lateral acceleration 406b and the lateral jerk 406c, as defined above. The lateral acceleration 406b can be detected by an accelerometer 204b integrated into the vehicle 100, and the lateral jerk 406c can be calculated as the first derivative of the lateral acceleration 406b. The yaw rate 406d, e.g., the rotation during yaw 302c, can also be derived from the rotation detected by the accelerometer 204b.

[0035] Other input signals may include a vehicle speed 406e, measured by a speed sensor 204a, which measures the rotation of one or more wheels 300a-300d or another component of the vehicle's powertrain 100. A currently selected driving mode 406f of the vehicle may also be used as input. In some implementations, the steering angle 406g and longitudinal acceleration 406h (e.g., as detected by the accelerometers 204b or based on driver inputs at an accelerator and brake pedal) are also used as input signals.

[0036] As mentioned above, there are a large number of input signals 406a-406h. The advantages of the approach described herein can be achieved by using only two or more of the input signals 406a-406d and the vehicle speed 406e. In one example, the steering speed 406a, the lateral acceleration 406b, and the lateral jerk 406c are used together with the vehicle speed 406e. However, further refinements can be achieved by using one or more additional input signals from input signals 406a-406h, as described in detail below.

[0037] Some of the input signals are referred to as "input signals relating to the lateral roll of the vehicle body" and may include, for example, the steering speed 406a and one or more of the lateral acceleration 406b, lateral jerk 406c, or yaw rate 406d, such as at least the lateral acceleration 406b and the lateral jerk 406c. The input signals relating to the lateral roll of the vehicle body may be fed into a normalization stage 408. Normalizing the input signals may include calculating the absolute value of each input signal and scaling the absolute value of the input signal such that each input signal is only between 0 and 1. For example, an input signal relating to the lateral roll of the vehicle body may be normalized according to (|S| / SF), where |S| is the absolute value of the signal (e.g., a sample of the signal) and SF is a scaling factor for the input signal.Normalization can involve restricting the normalized value to a value between 0 and 1. If |S| cannot possibly exceed SF and / or a normalized value greater than 1 is tolerated, (|S| / SF) can be used. Otherwise, other clamping methods can be used (e.g., minimum(|S| / SF,1,(2 / π)*atan(|S| / SF)).

[0038] The SF value can be selected experimentally. For example, a prototype of vehicle 100 can be subjected to handling tests that include cornering at different speeds and with varying radii to determine the safe operating limits of vehicle 100 (e.g., avoiding rollover, skidding, understeer, oversteer, etc.). During such handling tests, values ​​for input signals relating to the body roll can be measured while vehicle 100 is operated within these safe operating limits, and the maximum magnitude of the measurements for an input signal (possibly reduced by a safety factor) can be used as the SF value for that input signal. As explained in detail below, the SF value can be selected based on such measurements and other considerations.

[0039] The output of normalization stage 408 is a set of two or more normalized signals corresponding to the two or more input signals relating to the lateral tilt of the vehicle body. The normalized signals can be processed by a combination stage 410 to obtain a single combined signal. The combination stage can combine the normalized signals by summing them to obtain the combined signal. Alternatively, the combination stage can combine the normalized signals by taking the maximum value of the normalized signals, for example, the maximum sample value of the normalized signals for a given time step.

[0040] The combined signal can be fed into a filter / deadband stage 412. The filter / deadband stage 412 can subject the combined signal to low-pass filtering. The input signals, which relate to the lateral tilt of the vehicle body, and consequently the combined signal, contain high-frequency components, e.g., noise, whereas the vehicle 100 has a relatively low frequency response, e.g., less than 2 Hz. Accordingly, the filter / deadband stage 412 can filter the combined signal with a low-pass filter to obtain a filtered signal. The low-pass filter can have a cutoff frequency (e.g., 3 dB cutoff frequency) between 1.5 and 2.5 Hz, between 1.8 and 2.2 Hz, or between 1.9 and 2.1 Hz.

[0041] The filter / deadband stage 412 can clamp the filtered signal to zero under certain conditions, i.e., within a deadband. For example, at high vehicle speeds, changes in attenuation behavior may not be beneficial for small fluctuations in the input signals related to the vehicle's body roll. Accordingly, the filter / deadband stage 412 can implement logic such as the following: if (FS[t] < F(V)), then FS[t] = 0, where FS[t] is a sample in the filtered signal, V is the vehicle speed 406e, and F(V) is a function of the vehicle speed that increases with increasing vehicle speed; for example, the width of the deadband increases with increasing speed. F(V) can be implemented as a mathematical function, a lookup table, or other logic.

[0042] The filter / deadband level 412 can be a function of the vehicle's driving mode 406f. For example, in a racing driving mode, where reducing body roll is more important than comfort, the deadband width may be reduced or eliminated entirely. In a comfort driving mode, where comfort is more important than reducing body roll, the deadband may be larger; for example, F(V) for the comfort driving mode at a given vehicle speed V is larger than F(V) for the racing driving mode.

[0043] The filtered signal output by the filter / deadband stage 412 can be input into a force calculation stage 414. The force calculation stage 414 uses the filtered signal and one or more other input signals besides the input signals relating to the lateral tilt of the vehicle body, such as the vehicle speed 406e and possibly the driving mode 406f. The output of the force calculation stage 414 is a common damping force, which is used in subsequent stages to determine the specific damping force 404 for each valve 328a, 328b of each damper 324.

[0044] Force calculation stage 414 can calculate the common damping force using a table 414a, which maps a common damping force based on a value of the filtered signal to a common damping force value and the vehicle speed 406e. Table 414a can be a three-dimensional table that provides a common damping force for a value of the filtered signal, the vehicle speed 406e, and the driving mode 406f. Table 414a has a limited number of entries, so interpolation can be used. Table 414a can also be replaced by a mathematical function or program logic to select the common damping force based on input variables (filtered signal, speed, and possibly driving mode).

[0045] Table 414a provides a single data structure that takes into account speed and inputs related to the body roll to define the vehicle's handling characteristics with respect to the dampers 324. Specifically, Table 414a provides a single data structure for handling transient body roll resulting from cornering initiation, cornering exit, and steering angle changes during a turn. The table therefore offers a designer a convenient data structure for testing possible vehicle behaviors when tuning the vehicle's handling characteristics with respect to the dampers 324.

[0046] The common damping force output by force calculation stage 414 can be input into a left / right adjustment stage 416. Left / right adjustment stage 416 can also use the steering speed 406a and possibly the steering angle 406g as input. Left / right adjustment stage 416 determines the sign of the damping force (e.g., compression force 310 or rebound force 312) exerted by the damper 324 of each wheel 300a-300d and can make further adjustments to the common damping force. The output of left / right adjustment stage 416 can be a left damping force and a right damping force.

[0047] As mentioned above, normalization stage 408 can take the absolute value of the input signals relating to the lateral tilt of the vehicle body, so that the common damping force is independent of the direction of the lateral tilt. Accordingly, left / right adjustment stage 416 can determine the sign (e.g., compression force 310 = positive; rebound force 312 = negative) of the left and right damping forces, with the magnitude of the force being determined based on the common damping force.

[0048] For example, a positive steering speed can be defined as increased steering to the left, and a negative steering speed as increased steering to the right. Similarly, a positive steering angle can be defined as steering to the right of the straight-ahead position of the steered wheels, and a negative steering angle as steering to the left of the straight-ahead position. The left / right adjustment stage 416 can use the steering speed 406a and possibly the steering angle 406g to determine the left and right damping forces.

[0049] For example, a positive steering speed (to the left) can indicate a tendency for the vehicle body to roll to the right, so the right damper force is positive (compression force 310 not equal to zero) and the left damper force is negative (rebound force 312 not equal to zero). A negative steering speed (to the right) can indicate a tendency for the vehicle body to roll to the left, so the left damper force is positive and the right damper force is negative.

[0050] The magnitude of the left damper force and the right damper force can be set to equal to the common damper force, half the common damper force, or another function of the common damper force. For example, the positive left and right damper force can be set to P*C, and the negative left and right damper force can be set to N*C, where C is the common damper force and P and N are predetermined values ​​that can be unequal. For example, P can be greater than N.

[0051] The left / right adjustment stage 416 can also use the steering angle 406g as input. For example, the left and right damping forces determined as described above can be adjusted based on the steering angle 406g. In one application, in response to a zero crossing of the steering angle 406g, e.g., when changing from a right turn to a left turn, the left and right damping forces can be increased relative to the value based on the common damping force. In this way, the corresponding valves 328a and 328b close more quickly in anticipation of a greater damping force requirement further along the curve, causing the pressure in cylinder 326 to begin rising earlier and compensating for the delay associated with the change in the states of valves 328a and 328b.

[0052] The left and right damping forces determined by the left / right adjustment stage 416 can be entered into a front / rear adjustment stage 418, which generates the damping forces 404. The front and rear suspensions 120 can differ (e.g., different spring constants), and the weight distribution between the front wheels 300a, 300b and the rear wheels 300c, 300d can also differ. Accordingly, the left damping force can be processed by the left / right adjustment stage 416 to obtain a front left damping force 404 and a rear left damping force 404. The right damping force can be processed by the left / right adjustment stage 416 to obtain a front right damping force 404 and a rear right damping force 404.

[0053] For example, depending on the vehicle's load or inherent weight distribution, the rear wheels 300c, 300d may be more heavily loaded than the front wheels 300a, 300b. Accordingly, the front left damping force 404 can be calculated as F*LD and the rear left damping force can be calculated as R*LD, where LD is the left damping force and F and R are values ​​chosen to achieve a desired ratio between the front and rear damping forces. For example, R may be greater than F if the rear wheels 300c, 300d are more heavily loaded than the front wheels 300a, 300b. Similarly, the front right damping force 404 can be calculated as F*RD and the rear right damping force can be calculated as R*RD, where RD is the right damping force.

[0054] In some embodiments, the damping forces 404 can be further adjusted based on the longitudinal acceleration. For example, during positive acceleration, the load is transferred from the front wheels 300a, 300b to the rear wheels 300c, 300d. During negative acceleration (e.g., braking), the load is transferred from the rear wheels 300c, 300d to the front wheels 300a, 300b. The damping force 404 can be increased for the wheel 300a-300d that is subjected to a greater load due to the acceleration and decreased for the wheel 300a-300d that is subjected to a lesser load due to the acceleration.

[0055] For example, the magnitude of the front left damping force 404 and the front right damping force 404 can be adjusted or scaled by GF(a), and the rear left damping force 404 and the rear right damping force 404 can be increased or scaled by GR(a), where a is the acceleration, GF(a) is a function of the acceleration that decreases as acceleration increases, and GR(a) is a function of the acceleration that increases as acceleration increases.

[0056] Command stage 400 uses the damper forces 404 to generate the valve commands 402. For example, a positive damper force 404 corresponding to wheel 300a-300d causes the valve 328a of the damper 324 corresponding to these wheels 300a-300d to close in order to achieve a compression force 310 equal in magnitude to the positive damper force 404, and the valve 328b to open in order to reduce the rebound force 312. A negative damping force 404, corresponding to a wheel 300a-300d, causes the valve 328a of the damper 324, corresponding to the wheel, to open in order to reduce the compression force 310, which is equal in magnitude to the positive damping force 404, and the valve 328b to close in order to increase the rebound force 312 in accordance with the magnitude of the negative damping force 404.

[0057] For example, command level 400 can generate valve commands 402 as follows: • A positive front left damper force 404 can cause a corresponding closing of valve 328a and opening of valve 328b, corresponding to wheel 300a, to be commanded. • A negative front left damper force can cause a corresponding opening of valve 328a and closing of valve 328b, corresponding to wheel 300a, to be commanded. • A positive front right damper force 404 can cause a corresponding closing of valve 328a and opening of valve 328b, corresponding to wheel 300b, to be commanded. • A negative front right damper force 404 can cause a corresponding opening of valve 328a and closing of valve 328b, corresponding to wheel 300b, to be commanded. • A positive rear left damper force 404 can cause a corresponding closing of valve 328a and opening of valve 328b, corresponding to wheel 300c, to be commanded. • A negative rear left damper force 404 can cause a corresponding opening of valve 328a and closing of valve 328b, corresponding to wheel 300c, to be commanded. • A positive rear right damper force 404 can cause a corresponding closing of valve 328a and opening of valve 328b, corresponding to wheel 300d, to be commanded. • A negative rear right damper force 404 can cause a corresponding opening of valve 328a and closing of valve 328b, corresponding to wheel 300d, to be commanded.

[0058] The valve commands 402 can be entered directly into actuators that control the opening and closing of the valves 328a, 328b, or can be used as target specifications by one or more controllers that control the actuators.

[0059] The system made of Fig. Figure 4 is only an example, and various modifications can be made to further refine its functionality. For instance, normalization stage 408 can be used to change the weighting of input signals related to the body roll (steering speed 406a, lateral acceleration 406b, lateral jerk 406c, and yaw rate 406d). In one approach, the SF value used to normalize an input signal can be selected by a scaling factor selection stage 420 based on the driving mode 406f. In one example, in the first driving mode (e.g., race mode), the emphasis can be placed on steering speed 406a to reduce body roll and allow for better response to driver inputs.Accordingly, the SF value used to normalize steering speed 406a can be reduced compared to other driving modes, resulting in a greater contribution of steering speed 406a to the overall damping force. In a second driving mode (e.g., Comfort mode), the focus may be more on comfort than on body roll reduction and responsiveness, so the SF value used to normalize steering speed 406a may be higher than the SF value used for Race mode.

[0060] In another exemplary modification, the input signals relating to the vehicle body's lateral tilt can be shaped (e.g., scaled, filtered, processed according to a transfer function, etc.) based on one or more other input signals, such as the vehicle speed 406e and the driving mode 406f, either before normalization by the normalization stage 408 or instead of the normalization stage's function. The shaping of the input signals relating to the vehicle body's lateral tilt can be based on lookup tables, a mathematical function, programmed logic, or another approach.

[0061] In another exemplary modification, the order of certain steps can be reversed. For example, scaling with the scaling factor SF can be performed in the normalization phase before the absolute value is determined. The order of filtering and clamping within a deadband can also be reversed compared to the order described above with respect to the filter / deadband stage 412. The order of the left / right adaptation stage 416 and the front / rear adaptation stage 418 can also be reversed. Accordingly, a front damping force and a rear damping force can first be calculated based on the weight distribution, the suspension configuration, and / or the longitudinal acceleration 406 h, as described above.The front damping force can then be used to calculate the front left damping force 404 and the front right damping force 404 based on the steering speed 406a and possibly the steering angle 406g. The rear damping force can then be used to calculate the rear left damping force 404 and the rear right damping force 404 based on the steering speed 406a and possibly the steering angle 406g, as described above.

[0062] The Fig. 5A and Fig. Section 5B contains diagrams of the input signals relating to the lateral tilt of the vehicle body and illustrates the operation of the system. Fig. 5. In Fig. 5A is diagram 500a a diagram of steering speed (degrees per second), diagram 500b a diagram of lateral acceleration (meters per second squared), and diagram 500c a diagram of lateral jerk (meters per second cubed). Fig. Diagram 5B is diagram 502a, a diagram of the normalized steering speed; diagram 502b, a diagram of the normalized lateral acceleration; and diagram 502c, a diagram of the normalized lateral jerk. Diagram 502d is a diagram of the combined signal obtained from the normalized input signals. The diagrams of Fig. 5A and Fig. 5B corresponds to a cornering maneuver that includes turning in, smooth cornering (e.g. with a relatively constant steering angle), a correction in the middle of the maneuver, and straightening the steered wheels at the end of the cornering maneuver.

[0063] As can be easily seen, the magnitudes of these signals are very different before normalization. Furthermore, as can be seen, after normalization, the magnitude of the normalized signals varies throughout the entire cornering process. For example, the normalized steering speed (Diagram 502a) is dominant during the initial turn, while the normalized lateral acceleration (Diagram 502b) is dominant during steady cornering. During the mid-corner correction and during straightening out, all three normalized input signals contribute to the combined signal and exhibit peaks that occur at different times. Using the approach described above, the combined signal obtained from the normalized signals captures the contribution of the input signal relating to the body roll that is dominant at any given phase of the cornering process.

[0064] The combined signal also serves to smooth out fluctuations in the individual input signals, resulting in more consistent control of the dampers 324, particularly during mid-corner corrections and straight-out maneuvers. For example, during mid-corner corrections, the normalized steering speed will tend to dictate the slope of the combined damping force, with further shaping provided by the normalized lateral acceleration and lateral jerk to reflect vehicle behavior. During straight-out maneuvers, all three normalized input signals are blended to ensure stable support for the vehicle as it exits the turn.

[0065] The descriptions of the various embodiments of this disclosure are presented for illustrative purposes. Many modifications and variations will be obvious to the person skilled in the art without affecting the scope and spirit of the described embodiments. The terminology used herein has been chosen to explain the principles of the embodiments, their practical application, or the technical improvement over technologies available on the market, or to enable other persons skilled in the art to understand the embodiments disclosed herein.

[0066] The foregoing refers to the embodiments presented in this disclosure. However, the scope of this disclosure may extend beyond the specifically described embodiments. Instead, any combination of features and elements, regardless of whether they relate to different embodiments, is considered for the implementation and practice of the presented embodiments. Furthermore, while the embodiments disclosed herein may have advantages over other possible solutions or over the prior art, the embodiments may have some advantages or no particular advantage at all. Therefore, the aspects, features, embodiments, and advantages discussed herein are merely illustrative.

[0067] While the foregoing relates to embodiments of the present disclosure, other and further embodiments may be elaborated without deviating from the basic scope of protection, and the scope of protection is determined by the following claims. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 682,747

[0001]

Claims

[1] Control system for use in a vehicle, wherein the control system is configured to: Receiving two or more input signals relating to the lateral tilt of the vehicle body; Combining the two or more input signals to obtain a combined signal; Calculating a common damping force based on the combined signal and the vehicle's speed; Processing the combined damping force to calculate a damping force corresponding to each wheel of a multitude of vehicle wheels; and Specifying the operation of a vehicle damper that corresponds to each of the vehicle's multiple wheels, according to the damping force corresponding to each wheel. [2] Control system according to claim 1, wherein the control system is configured to normalize the two or more input signals to obtain two or more normalized signals and to combine the two or more normalized signals to obtain the combined signal. [3] Control system according to claim 2, wherein the control system is configured to normalize each input signal of the two or more input signals by dividing an absolute value of each input signal by a scaling factor corresponding to each input signal. [4] Control system according to claim 2, wherein the control system is configured to combine the two or more normalized signals by summing the two or more normalized signals. [5] Control system according to claim 2, wherein the control system is configured to combine the two or more normalized signals by taking a maximum of the two or more normalized signals. [6] Control system according to claim 1, wherein the control system is configured to calculate the common damping force based on the combined signal and the speed of the vehicle using a lookup table. [7] Control system according to claim 1, wherein the control system is configured to calculate the common damping force based on the combined signal, the speed of the vehicle and a driving mode of the vehicle. [8] Control system according to claim 1, wherein the two or more input signals include a steering speed and a lateral acceleration of the vehicle. [9] Control system according to claim 8, wherein the two or more input signals include a transverse jerk. [10] Control system according to claim 9, wherein the two or more input signals include a yaw rate of the vehicle. [11] Control system according to claim 1, wherein the control system is configured to process the common damping force in order to calculate, for each wheel of the plurality of wheels of the vehicle, the damping force corresponding to the respective wheel by: Calculating a left damping force and a right damping force from the common damping force based on a steering speed of the vehicle; and Calculate the damping force corresponding to each left wheel of the plurality of wheels, according to the left damping force, and calculate the damping force corresponding to each right wheel of the plurality of wheels, according to the right damping force. [12] Control system according to claim 11, wherein the control system is configured to calculate the left damping force and the right damping force from the common damping force based on the steering speed and the steering angle of the vehicle. [13] Control system according to claim 11, wherein the control system is configured to calculate the damping force corresponding to each left wheel of the plurality of wheels according to the left damping force and to calculate the damping force corresponding to each right wheel of the plurality of wheels according to the right damping force by: Calculating the damping force for a left front wheel of a plurality of wheels and for a left rear wheel of a plurality of wheels according to the left damping force and a longitudinal acceleration of the vehicle; and Calculating the damping force for a right front wheel of the multitude of wheels and for a right rear wheel of the multitude of wheels according to the right damping force and the longitudinal acceleration of the vehicle. [14] Control system according to claim 1, wherein the control system is configured to: Calculating the combined damping force based on the combined signal and the vehicle speed by filtering the combined signal using a low-pass filter to obtain a filtered signal; and Calculating the common damping force based on the filtered signal and the vehicle's speed. [15] Control system according to claim 14, wherein the low-pass filter has a cutoff frequency of 1.5 Hz to 2.5 Hz. [16] Vehicle, comprising: a chassis; a large number of wheels; a plurality of suspensions connecting the plurality of wheels to the chassis, each suspension of the plurality of suspensions including a damper; and a control system configured to: Receiving two or more input signals relating to the lateral tilt of the vehicle body; Combining the two or more input signals to obtain a combined signal; Calculating a common damping force based on the combined signal and the vehicle's speed; Processing the combined damping force to calculate a damping force corresponding to each wheel of a multitude of vehicle wheels; and Specifying the operation of a vehicle damper that corresponds to each of the vehicle's multiple wheels, according to the damping force corresponding to each wheel. [17] Vehicle according to claim 16, wherein the control system is configured to normalize the two or more input signals to obtain two or more normalized signals and to combine the two or more normalized signals to obtain the combined signal. [18] Vehicle according to claim 17, wherein the control system is configured to combine the two or more normalized signals by summing the two or more normalized signals or by taking a maximum of the two or more normalized signals. [19] Vehicle according to claim 16, wherein the control system is configured to calculate the common damping force based on the combined signal, the speed of the vehicle and a driving mode of the vehicle. [20] Methods for damper control, comprising: Received, by a vehicle's control system, from two or more input signals relating to the lateral tilt of the vehicle body; Combine, through the control system, the two or more input signals to obtain a combined signal; Calculate, through the control system, a common damping force based on the combined signal and a speed of the vehicle; Processing, by the control system, the common damping force in order to calculate a damping force corresponding to each wheel of a multitude of wheels of the vehicle; and Specifying, through the control system, the functioning of a damper of the vehicle, which corresponds to each wheel of the multitude of wheels of the vehicle, according to the damping force that corresponds to each wheel.

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