A method for controlling an active shock absorber in a road vehicle equipped with roll angle and pitch angle adjustment functions.

Abstract

To provide a method for controlling an active shock absorber (6) of a road vehicle (1).SOLUTION: Each active shock absorber (6) is a part of a suspension (5) that connects a vehicle body frame (4) to a hub (3) of a wheel (2) and is provided with an actuator (10). A control method includes: a step which obtains longitudinal acceleration (ax) and lateral acceleration (ay) of a road vehicle (1); a step which determines a desired roll angle (φTGT) on the basis of the lateral acceleration (ay); and a step which determines a desired pitch angle (θTGT) on the basis of the longitudinal acceleration (ax).SELECTED DRAWING: Figure 7

Description

[Technical Field] 【0001】 [Cross-reference of related applications] This patent application claims priority to Italian Patent Application No. 102021000015182, filed on 10 June 2021, the entirety of which disclosures are incorporated herein by reference. 【0002】 The present invention relates to a method for controlling the active shock absorber of a road vehicle. [Background technology] 【0003】 The movement of a passive shock absorber is entirely determined by the stress transmitted from the road surface; therefore, a passive shock absorber is at the mercy of the road surface. In recent years, active shock absorbers have been proposed that can perform autonomous movement (i.e., completely separate from the stress transmitted from the road surface) in response to the movement caused by the stress transmitted from the road surface. The purpose of autonomous movement performed by an active shock absorber is to maximize the dynamic performance of a vehicle on the road or to improve the driving comfort of a vehicle on the road in response to the stress transmitted from the road surface (in the same vehicle on the road, the active shock absorber can be made to pursue different goals depending on the driving style selected by the driver). 【0004】 An active shock absorber is equipped with its own electric or hydraulic actuator, which can be controlled to move autonomously (i.e., completely independently of stress transmitted from the road surface). For example, by controlling the actuator of the active shock absorber, the vehicle frame of a road vehicle can be lowered or raised independently on each wheel (even when the vehicle is stationary). 【0005】 Patent Document 1 describes a method for controlling the attitude of a vehicle equipped with an active suspension, which includes actuators that generate forces, and a control unit adjusts the change in attitude by controlling the force generated by each actuator. The control unit sets longitudinal and transverse virtual control lines that change to pursue target pitch and target roll, thereby controlling the attitude of the vehicle so that the attitude of the vehicle approaches the virtual control lines as closely as possible. 【0006】 Patent Document 2 discloses a method for controlling the attitude of a moving vehicle, in which the target pitch rate is calculated according to the actual roll rate, and pitch suppression is performed with priority over roll suppression. 【0007】 Patent Document 3 describes a method for braking or accelerating a road vehicle for the purpose of transporting passengers. [Prior art documents] [Patent Documents] 【0008】 [Patent Document 1] U.S. Patent Application Publication No. 2009037051(A1) [Patent Document 2] U.S. Patent Application Publication No. 2012078470(A1) [Patent Document 3] German Patent Application Publication No. 102020000441(A1) Specification [Overview of the project] [Problems that the invention aims to solve] 【0009】 The object of the present invention is to provide a method for controlling an active shock absorber of a road vehicle that maximizes performance even when driving in conditions close to the grip limit. [Means for solving the problem] 【0010】 According to the present invention, a method for controlling an active shock absorber of a road vehicle is provided, as described in the appended claims. 【0011】 Preferred embodiments of the present invention are described in the attached claims, which form an integral part of this specification. [Brief explanation of the drawing] 【0012】 [Figure 1] This is a schematic plan view of a road vehicle equipped with four active shock absorbers controlled according to the present invention. [Figure 2] Figure 1 is a schematic diagram showing the suspension of a vehicle traveling on the road. [Figure 3] This is a schematic diagram showing a vehicle on a road, as depicted in Figure 1, as it travels along a curve, with its trajectory, speed, steering angle, and attitude angle highlighted. [Figure 4] Figure 1 is a control diagram of the control unit implemented in the road-going vehicle. [Figure 5] This figure shows the variation in the desired drop at the center of gravity of the road-traveling vehicle in Figure 1 when the vertical acceleration changes. [Figure 6] This figure shows the variation in the desired drop of the center of gravity of the road-traveling vehicle in Figure 1 when the lateral acceleration changes. [Figure 7] This figure shows the variation in the desired roll angle of the road-traveling vehicle in Figure 1 when the lateral acceleration changes. [Figure 8] This figure shows the variation in a desired pitch angle for a road-traveling vehicle as the longitudinal acceleration changes. [Modes for carrying out the invention] 【0013】 Next, the present invention will be described with reference to the attached drawings illustrating non-limiting embodiments thereof. 【0014】 In Figure 1, reference numeral 1 indicates a road vehicle that generally has two front wheels 2 and two rear wheels 2. 【0015】 The road vehicle 1 is equipped with a powertrain system (known but not shown herein) which may include an internal combustion engine and / or one or more electric motors. 【0016】 The hub 3 of each wheel 2 (schematically shown in Figure 2) is connected to the vehicle frame 4 of the road vehicle 1 by the suspension 5 (partially shown in Figure 1). The suspension 5 is equipped with an (electronically controlled) active shock absorber 6 that can perform autonomous movement (i.e., completely separate from the stress transmitted from the road surface) in response to the movement caused by the stress transmitted from the road surface. 【0017】 As shown in Figure 2, each active shock absorber 6 comprises an element 7 defining one end of the active shock absorber 6 and an element 8 defining the other end of the active shock absorber 6, which is mounted to slide relative to element 7 so as to be able to move linearly parallel to element 7. Each active shock absorber 6 is equipped with a spring 9, which is connected between the two elements 7 and 8 and expands and contracts when these two elements 7 and 8 move linearly parallel to each other. Finally, each active shock absorber 6 is equipped with an electric actuator 10, which is configured to cause the active shock absorber 6 to move autonomously between elements 7 and 8 (i.e., completely separate from stress transmitted from the road surface), which means that it can generate a force F applied between elements 7 and 8. As one embodiment, the active shock absorber 6 may be of the type described in U.S. Patent Application Publication No. 2008190104(A1) and International Publication No. 2014145215(A2). Each active shock absorber 6 is equipped with a position sensor 11 (e.g., a potentiometer), which measures the current relative position p of the two elements 7 and 8. 1...4 This provides an exact measurement representing the amount of translation of element 8 relative to element 7. 【0018】 The road vehicle 1 is equipped with an electronic control unit (ECU) 12 that controls the actuator 10 of the active shock absorber 6, as described below. From a physical standpoint, this control unit 12 may consist of a single device or multiple devices that are isolated from each other and communicate via the CAN network (Controller Area Network: CAN) of the road vehicle 1. 【0019】 As shown in Figure 1, the road vehicle 1 is equipped with a longitudinal accelerometer 13 and a transverse accelerometer 14, which are attached to the vehicle frame 4, that is, they are firmly fixed to the vehicle frame 4 so as to operate integrally with the vehicle frame 4, and the longitudinal acceleration a in the vehicle frame 4 (i.e., the road vehicle 1) x and lateral acceleration a y They are configured to measure the longitudinal acceleration a x and lateral acceleration a y Both can be integrated into a single sensor (e.g., a 3-axis accelerometer). The control unit 12 controls the longitudinal acceleration a x and lateral acceleration a y To periodically read the current values, the accelerometers 13 and 14 are connected (either directly or indirectly via the BUS network of the road vehicle 1). 【0020】 The control unit 12 can periodically read the current value of the steering angle α (shown in Figure 3) of the front wheels 2 (typically via the BUS network of the road vehicle 1). 【0021】 According to FIG. 4, the control unit 12 implements an estimation block 15 that measures the actual attitude angle β of the road vehicle 1 (i.e., the angle formed between the longitudinal axis x of the road vehicle 1 and the direction of the traveling speed V of the road vehicle 1 at the center of gravity B) in a known manner. As an example, the estimation block 15 of the control unit 12 estimates the trajectory T followed by the road vehicle 1 using the measurement values provided in real time by a three-axis gyroscope and a GPS tracking unit. Specifically, the trajectory T is obtained by integrating the acceleration measured by the three-axis gyroscope twice over time, and the position error generated during the integration process is periodically canceled using the measurement values provided by the GPS tracking unit. Further, the estimation block 15 of the control unit 12 estimates the traveling speed V of the road vehicle 1 at the center of gravity B using the measurement values provided in real time by the three-axis gyroscope. Specifically, the speed V of the road vehicle 1 at the center of gravity B is obtained by integrating the acceleration measured by the three-axis gyroscope once over time (it is confirmed whether the traveling speed V of the road vehicle 1 at the center of gravity B actually deviates from the trajectory T followed by the road vehicle 1, and if it does and a significant deviation is observed, a calculation for correcting the parameters used is repeatedly performed at least once additionally). 【0022】 The control unit 12 implements an estimation block 16 that measures, in a known manner, the yaw angle ψ (i.e., the vibration angle of the road vehicle 1 around the longitudinal axis passing through the center of gravity B) and, substantially, the yaw speed Vψ, i.e., the change in the yaw angle ψ over time (the yaw speed Vψ can be measured by deriving the yaw angle ψ over time). According to an effective embodiment, the yaw speed Vψ can be measured and provided by the same sensor incorporating two accelerometers 13 and 14, which means that the integrated sensor provides, in addition to the longitudinal acceleration a x [[ID=�]]and the lateral acceleration a y also the yaw speed Vψ, and the yaw angle ψ can be obtained by integrating the yaw speed Vψ over time. 【0023】 As shown in Figure 4, the control unit 12 implements a calculation block 17, which calculates the position p of the four active shock absorbers 6 provided by the position sensor 11. 1...4 , the longitudinal acceleration a provided by the longitudinal accelerometer 13 x , the lateral acceleration a provided by the lateral accelerometer 14 y The calculation block 17 receives the attitude angle β provided by estimation block 15 and the yaw velocity Vψ provided by estimation block 16 as input. The calculation block 17 calculates the desired decrease h of the center of gravity B in a manner described in more detail below. b-TGT That is, a value (usually expressed in mm) is determined that indicates the degree to which the center of gravity B should be lowered relative to the standard position indicated by the center of gravity B when there is no external interference (for example, when the road vehicle 1 is stationary). Furthermore, the calculation block 17 determines the desired roll angle φ in the manner described in more detail below. TGT and the desired pitch angle θ TGT We seek. 【0024】 Desired decrease h of the center of gravity B b-TGT The objective is to lower the road vehicle 1 under dynamic conditions that result in better performance by reducing the transmission of absolute load, and as a final effect, increase the overall grip force of the tires of the wheels 2 (i.e., instead of having wheels 2 that receive a large stress and wheels 2 that receive a small stress, each wheel 2 receives essentially the same amount of stress), and here the reduction in load transmission occurs in both the case of lateral slip and longitudinal slip, and as a result the maximum lateral acceleration a y and maximum longitudinal acceleration a x The performance related to this will be improved. Therefore, by reducing the transmission of vertical loads, a greater force will be transmitted to the ground, and as a result, the maximum vertical acceleration a x As this increases, the desired decrease h of the center of gravity B b-TGT Furthermore, this will have a positive effect on both the acceleration and braking phases. 【0025】 Desired roll angle φ TGTThe purpose of controlling this is to reduce both dynamic and static roll, that is, to define both the slope of the static roll and the desired dynamic behavior as the input frequency changes. 【0026】 Desired pitch angle θ TGT The purpose of controlling the pitch is to reduce static and dynamic pitch, to change the attitude of the road vehicle 1 to optimize the aerodynamic point of action, and to dampen transient phenomena in braking actions in which the anti-lock braking system (ABS) of the wheels 2 intervenes. Reducing pitch and slowing down pitch dynamics leads to faster stabilization of the normal force and improves aerodynamic balance (and thus reduces the transmission of longitudinal loads), so these individual effects lead to improvements in the braking space. 【0027】 As shown in Figure 4, the control unit 12 implements a calculation block 18, which receives the desired decrease h of the center of gravity B as input from the calculation block 17. b-TGT , desired roll angle φ TGT , and the desired pitch angle θ TGT It receives the signal, and then each active shock absorber 6 is supposed to generate a force F expressed in Newtons. 1...4-TGT The target force value (i.e., the force target value) is determined. In other words, the electric actuator 10 of each active shock absorber 6 determines the corresponding desired force F 1...4-TGT In pursuit of the corresponding desired force F 1...4-TGT It is controlled to generate [something]. 【0028】 According to one preferred embodiment, the calculation block 18 uses a mathematical model of a road vehicle 1, which has an input variable (a desired decrease h of the center of gravity B). b-TGT , desired roll angle φ TGT and the desired pitch angle θ TGT Depending on the instantaneous value of (which is), the output variable (the desired force F generated by the active shock absorber 6) 1...4-TGT This provides the instantaneous value of ( ). 【0029】 Preferably, the calculation block 17 implemented in the control unit 12 calculates the desired decrease h of the center of gravity B. b-TGT , desired roll angle φ TGT , and the desired pitch angle θ TGT Since this is generally recalculated (updated) at a relatively low frequency in the range of 1 to 4 Hz, the calculation block 18 implemented in the control unit 12 uses the same update frequency as the calculation block 17 to obtain the desired force F 1...4-TGT It goes without saying that this is being recalculated (updated). 【0030】 The calculation block 17 implemented in the control unit 12 calculates the longitudinal acceleration a x and lateral acceleration a y Accordingly, the desired reduction h of the center of gravity B of the road vehicle 1. b-TGT To determine (as described above, the actuator 10 of each shock absorber 6, by the operation of the calculation block 18, the desired lowering of the center of gravity B h) b-TGT (It is controlled to obtain...). Specifically, calculation block 17 calculates the longitudinal acceleration a x In accordance only (i.e., lateral acceleration a) y Without considering the first contribution, and the lateral acceleration a y In accordance only (i.e., longitudinal acceleration a) x (Without considering) the second contribution is determined, and then the desired reduction h of the center of gravity B is determined. b-TGT We determine this by taking the larger of the absolute values ​​between the first and second contributions (i.e., selecting the contribution with the larger absolute value). In other words, the desired decrease h b-TGT This is equal to a contribution with a larger absolute value. 【0031】 According to Figure 5, calculation block 17 uses linear law L1 (shown in Figure 5) to calculate the longitudinal acceleration a x The desired decrease h of the center of gravity B according to the b-TGT (That is, the desired reduction h of the center of gravity B) b-TGT The first contribution of is determined. This linear law L1 is determined by the positive and negative longitudinal acceleration a x It is mirror-like symmetrical with respect to (the desired decrease h of the centroid B). b-TGT However, vertical acceleration ax (Since it is always negative regardless of the sign, it is symmetrical like a mirror), longitudinal acceleration a x As the absolute value of increases, the desired decrease h of the center of gravity B b-TGT This involves a proportional increase in longitudinal acceleration a. x When the absolute value of is less than the threshold TH1, the linear law L1 is the desired decrease of the centroid B to zero h b-TGT Accompanied by, longitudinal acceleration a x When the absolute value of is greater than the threshold TH2, a constant desired decrease h of the centroid B equals the maximum value VMAX1. b-TGT This is accompanied by, and also, longitudinal acceleration a x When the absolute value of is equal to the first threshold TH1, the longitudinal acceleration a x The desired decrease h of the centroid B until the maximum value VMAX1 is reached when the absolute value of is equal to the second threshold TH2. b-TGT This involves linearly varying the value. 【0032】 In the embodiment shown in Figure 5, the maximum value VMAX1 is equal to 20 mm (in Figure 5, the value VMAX1 is negative to indicate a decrease), the threshold TH1 is equal to 0.25 g, and the threshold TH2 is equal to 1 g, where the letter "g" represents the average gravitational acceleration measured on Earth, which by convention is 9.80665 m / s². 2 It corresponds to this. 【0033】 According to Figure 6, calculation block 17 uses the linear law L2 to calculate the lateral acceleration a y The desired decrease h of the center of gravity B according to the b-TGT (That is, the desired reduction h of the center of gravity B) b-TGT This determines the second contribution of ( ). This linear law L2 is for positive and negative lateral acceleration a y It is mirror-like symmetrical with respect to (the desired decrease h of the centroid B). b-TGT However, lateral acceleration a y (Since it is always negative regardless of the sign, it is symmetrical like a mirror), under all operating conditions, the lateral acceleration a y As the absolute value of increases, the desired decrease h of the centroid B b-TGTThis involves a proportional increase in the lateral acceleration a y The linear law L2 applies only when the absolute value of is zero, and the desired reduction of the centroid B to zero h b-TGT This is accompanied by, and also by a lateral acceleration a y When the absolute value of is zero, the lateral acceleration a y The desired decrease h of the center of gravity B until the maximum value VMAX2 occurs when the absolute value of is at its maximum. b-TGT This involves linearly varying the value. 【0034】 In the embodiment shown in Figure 6, the value VMAX2 is equal to 22.5 mm (in Figure 6, the value VMAX2 is negative to indicate that it is decreasing), and the lateral acceleration a y The value is reached when (its absolute value) is equal to 1.5g. 【0035】 As described above, calculation block 18 determines the desired decrease h of the center of gravity B. b-TGT Accordingly (similarly), the force target value F of the actuator 10 of each active shock absorber 6 1...4-TGT To determine this, a mathematical model of a road-going vehicle 1 is used, and as a result, the actuator 10 of each shock absorber is set to the corresponding force target value F 1...4-TGT It is controlled to pursue that goal. 【0036】 According to one preferred embodiment, the desired reduction h of the center of gravity B b-TGT is the vertical acceleration a x and lateral acceleration a y The desired reduction of the center of gravity B is determined according to both, but according to one different embodiment, b-TGT is the vertical acceleration a x In response only, or lateral acceleration a y It is determined solely by this. 【0037】 According to Figure 7, calculation block 17 uses the linear law L3 to calculate the lateral acceleration a y The desired roll angle φ depends only on the desired roll angle. TGT This is determined. This linear law L3 is for positive and negative lateral acceleration a yis symmetric like a mirror with respect to (i.e., when the lateral acceleration a y is positive, the roll angle φ TGT is always positive, and when the lateral acceleration a y is negative, the roll angle φ TGT is always negative), and also, every time the absolute value of the lateral acceleration a y increases by 1g, it involves linearly varying the desired roll angle φ TGT by a value in the range of 1.0° to 1.8° (preferably equal to 1.4°). This means that the linear rule L3 has a slope in the range of 1.0° / g to 1.8° / g, preferably equal to 1.4° / g (which is the variation of the angle per unit of acceleration). Therefore, the linear rule L3 involves proportionally varying the absolute value of the desired roll angle φ y as the absolute value of the lateral acceleration a TGT increases. Specifically, the linear rule L3 has a zero desired roll angle φ y only when the absolute value of the lateral acceleration a TGT is zero. In other words, the linear rule L3 linearly varies the desired roll angle φ y from a zero value when the absolute value of the lateral acceleration a y is zero to a maximum absolute value VMAX3 when the absolute value of the lateral acceleration a TGT is maximum. 【0038】 In the embodiment shown in FIG. 7, the absolute value of the value VMAX3 is in the range of 1.8° to 2.4°, preferably equal to 2.1°, and is reached when the lateral acceleration a y is equal to 1.5g (in terms of its absolute value). 【0039】 According to FIG. 8, the calculation block 17 determines the desired pitch angle θ x using the linear rule L4 based only on the longitudinal acceleration a TGT . This linear rule L4 is not symmetric with respect to a positive or negative lateral acceleration a y (i.e., the linear rule L4 is unbalanced towards a positive pitch angle θ TGT , which involves pulling down the front part of the road vehicle 1 and pulling up the rear part of the road vehicle 1), and also, the longitudinal acceleration ax For every 1g increase in the absolute value of θ, the desired pitch angle θ TGT This involves varying the value in the range of 1.2° to 2.0° (preferably equal to 1.6°), which means that the linear law L4 is in the range of 1.2° / g to 2.0° / g, and preferably has a slope (a variation in angle per unit of acceleration) equal to 1.6° / g. 【0040】 Linear law L4 is given by the longitudinal acceleration a x As the value of decreases, the desired pitch angle θ TGT This involves a proportional increase in longitudinal acceleration a. x When the value of is zero, the linear law L4 applies to positive pitch angles θ greater than zero. TGT Accompanied by, longitudinal acceleration a x When the value of is positive (vehicle 1 on the road is accelerating), and preferably greater than 0.3g, the linear law L4 is negative for the pitch angle θ TGT This is accompanied by, specifically, longitudinal acceleration a x When the value of is positive (i.e., vehicle 1 on the road is accelerating) and is in the range of 0.3g to 0.5g (preferably equal to 0.4g), the linear law L4 is zero pitch angle θ TGT It is accompanied by. 【0041】 In the embodiment shown in Figure 8, the linear law L4 determines the desired pitch angle θ when there is maximum deceleration and when there is maximum acceleration, respectively. TGT This is accompanied by a range of +2.0° to -0.5°. 【0042】 Zero roll angle φ TGT The zero pitch angle (i.e., equal to 0°) and the zero pitch angle (i.e., equal to 0°) correspond to the neutral state of the road vehicle 1, which occurs when the road vehicle 1 is stationary (parked) on a flat surface, i.e., completely stationary. 【0043】 As described above, the calculation block 18 determines the desired roll angle φ TGT and the desired pitch angle θ TGT Accordingly (similarly), the force target value F of the actuator 10 of each active shock absorber 61...4-TGT To determine this, a mathematical model of a road-going vehicle 1 is used, and as a result, the actuator 10 of each shock absorber is set to the corresponding force target value F 1...4-TGT It is controlled to pursue that goal. 【0044】 According to one preferred embodiment, the calculation block 18 (desired roll angle φ TGT Determine the desired roll angle φ TGT The force target value F of the actuator 10 of each active shock absorber 6 accordingly 1...4-TGT (To determine the desired roll angle φ) TGT The total anti-roll moment is determined accordingly (i.e., the desired roll angle φ). TGT The total anti-roll moment (which is the total anti-roll moment required to obtain the desired result) is determined, the total anti-roll moment distribution between the front axle (including the two front wheels 2) and the rear axle (including the two rear wheels 2) is determined, and then, according to the total anti-roll moment and according to the total anti-roll moment distribution between the front axle and the rear axle, the force target value F of the actuator 10 of each active shock absorber 6 is determined. 1...4-TGT Confirm. 【0045】 This total anti-roll moment is usually distributed symmetrically between the front and rear axles; that is, the anti-roll moment generated for the front axle is always equal to the anti-roll moment generated for the rear axle. It has been observed that an asymmetric distribution of this total anti-roll moment is advantageous, in which case the anti-roll moment generated for the front axle is different from the anti-roll moment generated for the rear axle. Furthermore, the distribution of the total anti-roll moment can be changed (by shifting a portion of the total anti-roll moment from the front axle to the rear axle, or from the rear axle to the front axle) according to the dynamics of the road vehicle 1. 【0046】 In one preferred embodiment, the total anti-roll moment distribution includes a lower limit that identifies an increase in the anti-roll moment of the rear axle, ranging from -12% to -6% (i.e., the anti-roll moment of the rear axle is 12% to 6% greater than the anti-roll moment of the front axle), and an upper limit that identifies an increase in the anti-roll moment of the front axle, ranging from +1.5% to +4% (i.e., the anti-roll moment of the front axle is 1.5% to 4% greater than the anti-roll moment of the rear axle). 【0047】 Calculation block 18 determines whether the road vehicle 1 is about to begin a curve or is already in the middle of a curve, and determines the total anti-roll moment distribution which becomes more unbalanced towards the rear axle when the road vehicle 1 is about to begin a curve or is already in the middle of a curve. Furthermore, calculation block 18 determines whether the road vehicle 1 is about to exit the curve, and determines the total anti-roll moment distribution which becomes less unbalanced towards the front axle when the road vehicle 1 is exiting the curve. 【0048】 Calculation block 18 determines whether the road vehicle 1 is exhibiting oversteer behavior, and if it is, it disrupts the balance of the total anti-roll moment distribution toward the front axle (in an attempt to bring the road vehicle 1 to a neutral state and counteract the oversteer behavior). Similarly, calculation block 18 determines whether the road vehicle 1 is exhibiting understeer behavior, and if it is, it disrupts the balance of the total anti-roll moment distribution toward the rear axle (in an attempt to bring the road vehicle 1 to a neutral state and counteract the understeer behavior). 【0049】 The total anti-roll moment introduced by roll control can be arbitrarily distributed between the front and rear axles. Choosing such a distribution affects the distribution of lateral load transmission between the two axles, but does not change the total amount transmitted. A distribution that becomes more unbalanced towards the rear axle typically delays the concentration of load on the front axle, thus increasing the maximum lateral acceleration. This configuration is suitable when the vehicle is about to enter a curve or is in the middle of a curve with pure sideslip. On the other hand, a distribution that shifts towards the front axle reduces the maximum lateral acceleration and promotes the concentration of load on the front axle, but at the same time prioritizes the rear axle, allowing for greater transmission of drag. This configuration is suitable during the tensile phase when exiting a curve. This anti-roll moment distribution can be dynamically changed to improve the condition of the road vehicle 1 at each stage of curve driving. For example, the anti-roll moment distribution may have values ​​of -8.5% (when the vehicle is about to start or is in the middle of a curve) and -3% (when exiting the curve), resulting in a variation of approximately 5%. 【0050】 By combining the control of the height of the center of gravity B and the control of the roll angle φ, it is possible to maintain the angle on the inside of the curve in a stationary state and keep the angle position on the outside of the curve unchanged, thereby achieving a desired roll angle φ that is half the roll angle φ of the uncontrolled road-going vehicle 1. TGT By performing this action (i.e., the active shock absorber 6 is turned off, so only in passive mode), the desired reduction h of the center of gravity B is obtained, which corresponds to half the angle reduction of the uncontrolled road vehicle 1 on the outside of the curve. b-TGT By applying this (i.e., the active shock absorber 6 is turned off, so only in passive mode), ideal behavior can be obtained. This function is effective for lateral acceleration a yIt depends on the angle of the curve, and specifically, when driving along a curve, a downward force acts on the inside of the curve to lower the center of gravity B and reduce roll, thus avoiding tension in the curve. However, in order to further reduce the roll inclination, it is also necessary to apply an upward force to the outside of the curve (this force is, in any case, much smaller than the force required for the inside of the curve). 【0051】 By combining control of the height of the center of gravity B with control of the static pitch angle θ, the center of gravity B is lowered by differentiating the height from the ground between the front and rear axles, thereby operating at the point of optimal aerodynamic efficiency. This functionality is important both in terms of achieving absolute performance, such as being able to increase the vertical load at the appropriate position according to a predetermined aerodynamic map, and in terms of energy efficiency, as it can reduce the resistance to the forward movement of the vehicle when traveling along a straight road. For example, this control does not involve any height imbalance between the two axles at speeds below 100 km / h, and at speeds above 100 km / h, it may not involve increasing the vertical load by lowering the front axle more than the rear axle, nor does it involve lowering the front axle when traveling along a straight road to reduce the resistance to forward movement. 【0052】 By combining control of the height of the center of gravity B with control of the static pitch angle θ, the braking space is also optimized. Lowering the center of gravity reduces the transmission of longitudinal loads, resulting in increased overall grip, while controlling both the static and dynamic pitch angles θ allows the normal force to stabilize more quickly. 【0053】 The embodiments described herein can be combined with each other, but this does not exceed the scope of protection of the present invention. 【0054】 The control method described above has various advantages. 【0055】 First, the above control method improves the performance of the road vehicle 1 when driving near the grip limit (typically on ruts), whether driving along a curve or a straight road (during acceleration when exiting a curve or deceleration when entering a curve). 【0056】 In particular, the above control method reduces both static and dynamic roll, as well as both static and dynamic pitch, and these reductions can be directly perceived by the driver, resulting in the driver feeling that they are driving the road vehicle 1 more stably and therefore more enjoyably (saferly). Furthermore, lowering the center of gravity B reduces the transmission of absolute load, thus allowing all wheels 2 to operate at their limits, which is decisive in improving performance. When static and dynamic pitch are reduced, braking performance improves. Dynamically distributing the anti-roll moment allows for optimal management of the tire friction ellipse of the wheels 2, thus improving braking performance. 【0057】 In other words, the control method described above achieves a pure performance improvement, shortens lap times, and enhances driving enjoyment, making the driver feel that the car is comfortable to drive. 【0058】 Furthermore, the above control method is extremely robust and safe under all driving conditions, meaning that there is essentially no risk of control errors that could cause abnormal vibrations or excessive extension of the suspension 5. 【0059】 Finally, the control method described above does not require significant computing power or a vast memory space, making it easy and economical to implement. [Explanation of symbols] 【0060】 1. Vehicles in motion 2 wheels 3 Hubs 4. Body frame 5. Suspension 6. Active Shock Absorbers 7 elements 8 elements 9 springs 10 Electric Actuators 11 Position Sensor 12 Control Unit 13. Longitudinal accelerometer 14 Lateral accelerometer 15 Estimated Blocks 16 Estimated Blocks 17 Calculation Block 18 Calculation Block a x Longitudinal acceleration a y lateral acceleration B Center of gravity α Steering angle β attitude angle h B-TGT Desired decrease in the center of gravity F force F TGT Desire φ Roll angle θ pitch angle ψ Yaw angle α Steering angle Vψ Yaw velocity L1 rule L2 law L3 rule L4 rule

Claims

[Claim 1] A control method for controlling an active shock absorber (6) of a road vehicle (1), Each of the active shock absorbers (6) is part of a suspension (5) that connects the vehicle frame (4) to the hub (3) of the wheel (2), and is equipped with an actuator (10), and the control method is The longitudinal acceleration (a) of the aforementioned road vehicle (1) ｘ ) and lateral acceleration (a ｙ The steps to find ) The aforementioned lateral acceleration (a ｙ Based on the desired roll angle (φ ＴＧＴ The steps to confirm ) and The longitudinal acceleration (a ｘ Based on the desired pitch angle (θ), ＴＧＴ The steps to confirm ) and The desired roll angle (φ ＴＧＴ ) and the desired pitch angle (θ ＴＧＴ The steps include controlling the actuator (10) of each of the active shock absorbers (6) to obtain, The desired roll angle (φ ＴＧＴ ), using a first linear rule (L3), is determined only according to the lateral acceleration (a ｙ ), and The desired pitch angle (θ) ＴＧＴ ) is calculated using the second linear law (L4) to determine the longitudinal acceleration (a ｘ It is determined solely based on the following: When the value of the longitudinal acceleration (ax) is zero, the second linear law (L4) is accompanied by a positive pitch angle (θTGT) greater than zero, and when the value of the longitudinal acceleration (ax) is positive, the second linear law (L4) is accompanied by a negative pitch angle (θTGT). A control method for controlling an active shock absorber (6) of a road vehicle (1). [Claim 2] The first linear law (L3) is defined as the lateral acceleration (a ｙ For every 1g increase in the absolute value of ), the desired roll angle (φ) is set to a value in the range of 1.0° to 1.8°. ＴＧＴ The control method according to claim 1, which involves varying the absolute value of ). [Claim 3] The first linear law (L3) is defined as the lateral acceleration (a ｙ As the absolute value of ) increases, the desired roll angle (φ ＴＧＴ The control method according to claim 1, which involves proportionally varying the absolute value of ). [Claim 4] The aforementioned lateral acceleration (a ｙ The first linear rule (L3) is zero only when the absolute value of ) is zero for the desired roll angle (φ ＴＧＴ The control method according to claim 1, which includes ) [Claim 5] The first linear law (L3) is defined as the lateral acceleration (a ｙ From the zero value when the absolute value of ) is zero, the lateral acceleration (a ｙ Up to the maximum value (VMAX3) when the absolute value of ) is at its maximum, the desired roll angle (φ ＴＧＴ The control method according to claim 1, comprising linearly varying the absolute value of ). [Claim 6] The second linear law (L4) is defined as the longitudinal acceleration (a ｘ Each time the absolute value of ) increases by 1g, the desired pitch angle (θ ＴＧＴ The control method according to claim 1, comprising increasing the value in the range of 1.2° to 2.0°. [Claim 7] The second linear law (L4) is defined as the longitudinal acceleration (a ｘ As the value of ) decreases, the desired pitch angle (θ ＴＧＴ The control method according to claim 1, which involves proportionally increasing ). [Claim 8] The longitudinal acceleration (a ｘ When the value of ) is positive and greater than at least 0.3g, the second linear rule (L4) is negative for the pitch angle (θ ＴＧＴ The control method according to claim 1, which includes ) [Claim 9] The longitudinal acceleration (a ｘ When the value of ) is positive and in the range of at least greater than 0.3g, the second linear rule (L4) is zero pitch angle (θ ＴＧＴ The control method according to claim 8, which includes ) [Claim 10] A control method for controlling an active shock absorber (6) of a road vehicle (1), Each of the active shock absorbers (6) is part of a suspension (5) that connects the vehicle frame (4) to the hub (3) of the wheel (2), and is equipped with an actuator (10), and the control method is The steps include determining the longitudinal acceleration (ax) and lateral acceleration (ay) of the road vehicle (1), The steps include determining a desired roll angle (φTGT) based on the aforementioned lateral acceleration (a y), The steps include determining a desired pitch angle (θTGT) based on the longitudinal acceleration (ax), The steps include controlling the actuator (10) of each of the active shock absorbers (6) to obtain the desired roll angle (φ TGT) and the desired pitch angle (θ TGT), The longitudinal acceleration (a ｘ ) and the lateral acceleration (a ｙ ) in accordance with the desired reduction (h ｂ－ＴＧＴ The steps to confirm ) and The desired reduction (h) of the center of gravity (B) ｂ－ＴＧＴ The steps include controlling the actuator (10) of each of the active shock absorbers (6) to obtain, The desired roll angle (φTGT) is determined using the first linear law (L3) and depends solely on the lateral acceleration (ay). The desired pitch angle (θ TGT) is determined using a second linear law (L4) and depends solely on the longitudinal acceleration (ax). A control method for controlling an active shock absorber (6) of a road vehicle (1). [Claim 11] The longitudinal acceleration (a ｘ ) and a further step to determine the first contribution based solely on that, The aforementioned lateral acceleration (a ｙ ) and a further step to determine the second contribution based solely on that, The desired decrease (h ｂ－ＴＧＴ The further step of determining that ) is equal to the contribution having a larger absolute value, The control method according to claim 10. [Claim 12] The first contribution is calculated using the third linear law (L1) to determine the longitudinal acceleration (a ｘ It is determined solely based on the following, and also, The second contribution is expressed using the fourth linear law (L2) as the lateral acceleration (a ｙ ) is determined solely based on the following: The control method according to claim 11. [Claim 13] The desired roll angle (φ ＴＧＴ ), the desired pitch angle (θ ＴＧＴ ) and the desired reduction (h) of the center of gravity (B) ｂ－ＴＧＴ ) in accordance with the force target value (F) of the actuator (10) of each active shock absorber (6). １．．．４－ＴＧＴ A further step is to use the mathematical model of the road vehicle (1) to determine the following: The corresponding force target value (F １．．．４－ＴＧＴ The further step of controlling the actuator (10) of each shock absorber in order to pursue the following: The control method according to claim 10. [Claim 14] A control method for controlling an active shock absorber (6) of a road vehicle (1), Each of the active shock absorbers (6) is part of a suspension (5) that connects the vehicle frame (4) to the hub (3) of the wheel (2), and is equipped with an actuator (10), and the control method is The steps include determining the longitudinal acceleration (ax) and lateral acceleration (ay) of the road vehicle (1), The steps include determining a desired roll angle (φTGT) based on the aforementioned lateral acceleration (a y), The steps include determining a desired pitch angle (θTGT) based on the longitudinal acceleration (ax), The steps include controlling the actuator (10) of each of the active shock absorbers (6) to obtain the desired roll angle (φ TGT) and the desired pitch angle (θ TGT), The desired roll angle (φ ＴＧＴ The steps include determining the total anti-roll moment according to the following, The steps include determining the distribution of the total anti-roll moment between the front axle and the rear axle, Depending on the total anti-roll moment and the distribution of the total anti-roll moment between the front axle and the rear axle, the force target value (F) of the actuator (10) of each active shock absorber (6) １．．．４－ＴＧＴ The steps to find ) The corresponding force target value (F １．．．４－ＴＧＴ The steps include controlling the actuator (10) of each shock absorber in order to pursue the following: The desired roll angle (φTGT) is determined using the first linear law (L3) and depends solely on the lateral acceleration (ay). The desired pitch angle (θ TGT) is determined using a second linear law (L4) and depends solely on the longitudinal acceleration (ax). A control method for controlling an active shock absorber (6) of a road vehicle (1). [Claim 15] The control method according to claim 14, wherein the distribution of the total anti-roll moment between the front axle and the rear axle may be asymmetrical, that is, the anti-roll moment generated with respect to the front axle may be different from the anti-roll moment generated with respect to the rear axle. [Claim 16] A further step is to determine whether the aforementioned road vehicle (1) is about to begin a curve, is in the middle of a curve, or is about to exit a curve. A further step is to determine the distribution of the total anti-roll moment, which becomes more unbalanced toward the rear axle when the road vehicle (1) is about to begin or is in the middle of a curve, The further step includes reducing the distribution of the total anti-roll moment, which becomes more unbalanced toward the rear axle, as the road vehicle (1) exits a curve, The control method according to claim 15. [Claim 17] A further step of determining whether the road vehicle (1) is exhibiting oversteer behavior, If the road vehicle (1) exhibits oversteer behavior, a further step is taken to disrupt the balance of the distribution of the total anti-roll moment toward the front axle, A further step is to determine whether the road vehicle (1) is exhibiting understeer behavior, If the road vehicle (1) exhibits understeer behavior, the further step includes disrupting the balance of the distribution of the total anti-roll moment toward the rear axle, The control method according to claim 15.

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