FIELD OF THE INVENTION

The invention relates to a method for managing active or semi-active suspension systems that used to enhance driving comfort and efficiency in vehicles

In particular, the invention related to a control method that enables the actuator, which is a suspension component of the vehicle, to dynamically respond to the vehicle's motions such as bounce, pitch and roll during driving.

PRIOR ART

Road profile characteristics during vehicle operation are among the most important parameters that affect driving comfort and safety. The road structure can vary depending on both urban and rural road conditions and environmental factors. In particular, the wavelength and amplitude of the road, relative to the unit length of the road, can excite the resonant frequencies of the vehicle's body and unsprung mass. Additionally, road conditions on stabilized roads or roads that have undergone repairs significantly influence the driving quality for the driver and passengers in terms of journey quality.

For instance, pitch and roll motions cause more discomfort for the driver and passengers compared to bounce motions. Therefore, in traditional suspension systems, the suspension geometry is designed to convert pitch motions into bounce motions.

Semi-active suspension systems are widely used in the automotive industry. The preference for these systems is due to the low energy consumption and cost effectiveness of the actuators that used in semi-active suspension systems. Additionally, active suspension systems are also preferred in applications where performance and comfort are key factors.

The most crucial parameter in determining the operational performance of the suspension system is the real-time control and rapid activation of active or semi-active actuators during driving. Forces that create the vertical dynamics of the vehicle and affect the vehicle during operation, such as bounce, pitch, and roll forces, are important forces that the suspension system needs to dampen for comfort and safety.

In conventional techniques, different control methods (centralized and regional methods) are commonly used in suspension systems. In centralized methods, calculations can be performed with sensors that placed at the center of gravity of the vehicle. In these applications, force decomposition transformations are carried out to separate forces into bounce, pitch, and roll forces. Because the calculations are done on a force basis, and some of the methods used in conventional techniques can only be controlled with damping coefficients, it is not possible to control centrally calculated force values with regional controllers.

In alternative applications (regional methods), the movement at each corner of the vehicle (suspension components) is modeled using sensors that located on each actuator, and control is carried out using different and independent controllers for each actuator. In this approach, only the total vertical motion at each corner of the vehicle can be controlled. Due to the interpretation of motion only in the vertical axis, it is not possible to determine the source of the motion (bounce, pitch, roll). As a result, prioritizing the bounce, pitch, and roll movements occurring on the vehicle body over each other cannot be achieved, and the suspension system cannot be efficiently controlled.

PCT/TR2021/051366 application number refers to a PCT document that discusses a control method developed for suspension systems to determine the road profile using the vehicle's existing equipment and prioritize the suspension system for the relevant profile to achieve maximum comfort and safety. The method developed for obtaining gain coefficients in the relevant application has been explained; however, it does not elaborate on how the calculation is performed using the data obtained from the suspension system.

As a result, all abovementioned problems have made it necessary to make an improvement in the relevant technical field.

AIM OF THE INVENTION

The present invention aims to eliminate the abovementioned problems and to make a development in the relevant technical field. The main objective of the invention is to model movements such as bounce, pitch, and roll in order to determine vehicle dynamics for evaluating and comparing the vehicle body collectively; and establish a method that allows to determine vehicle dynamics with control of active and semi-active suspension actuators used in damping in accordance with this.

Another objective of the invention is to establish a control method structure that prioritizes the forces of bounce, pitch, and roll over each other.

Another objective of the invention is to reduce the number of sensors on the vehicle.

Another objective of the invention is to control the suspension system using preestimated data.

Another objective of the invention is to present a suspension system control method that can work seamlessly in vehicles with two, three, four, or more wheel/axle configurations.

BRIEF DESCRIPTION OF THE INVENTION

The invention is related to suspension system control method for vehicles so as to fulfil all aims mentioned above and will be obtained from the following detailed description.

The invention relates a method to control the suspension system in vehicles to enabling the independent control of the actuators associated with the vehicle's wheels; by calculating the vertical-axis motion changes occurring at each corner of the vehicle, measured either from the vehicle's center or any reference point, characterized by; to establish the geometric relationship between each corner and adjacent corner of the mentioned vehicle, the geometric relationship is established using the bounce, pitch, and roll motion data obtained from at least one sensor expressed as a vector, between the mentioned sensor's associated reference point and at least one reference point associated with the mentioned actuator; the control of the mentioned actuators is achieved by determining in the vertical axis at least one of accelerations, or velocities of the bounce motion of each corner of the vehicle, along with at least one of the vertical positions, accelerations, or velocities of the pitch and roll angles.

In a preferred embodiment of the invention, it is chacterized by; controlling the relevant actuators in bounce, as well as the pitch and roll angles (velocity, acceleration), based on the vertical linear displacement (velocity, acceleration) of each end point of the vehicle.

In a preferred embodiment of the invention, it is chacterized by; at least one reference point which associated per corner of the four corners and linked to an actuator is calculated the bounce displacement of the vehicle, along with the pitch and roll angles between adjacent reference points.

In a preferred embodiment of the invention, it is chacterized by; the bounce displacement, pitch, and roll angles are measured through at least one sensor that located on a reference point on the vehicle and these measurements are then vectorially calculated and distributed to each reference point located at the farthest points from the reference point where the mentioned sensor is positioned.

In a preferred embodiment of the invention, it is chacterized by; the vectorial calculation of the displacement parameter associated with each actuator is calculated by multiplying the vectorial distance between the reference point where the sensor is located and the reference point associated with the actuator with the sine of the pitch angle; and by multiplying the vectorial distance between two reference points associated with two actuators on the same axis with the sine of the roll angle.

In a preferred embodiment of the invention, it is chacterized by; calculating the displacement parameter associated with each actuator vectorially using the bounce displacement parameter related to the vehicle.

In a preferred embodiment of the invention, it is chacterized by; performing the calculation based on the stroke speed of the respective actuator in the displacement parameter associated with each actuator.

In a preferred embodiment of the invention, it is chacterized by; performing the calculation by separating the stroke velocities related to the bounce, pitch, and roll motions of each actuator from each other.

In a preferred embodiment of the invention, it is chacterized by; the vectorial calculation of the displacement parameter associated with each actuator is calculated by multiplying the vectorial distance between the reference point where the sensor is located and the reference point associated with the actuator with the cosine of the pitch angle; and by multiplying the vectorial distance between two reference points associated with two actuators on the same axis with the cosine of the roll angle.

In a preferred embodiment of the invention, it is chacterized by; calculating the displacement parameter associated with each actuator vectorially using the bounce velocity parameter related to the vehicle.

In a preferred embodiment of the invention, it is chacterized by; calculating the displacement parameter associated with each actuator vectorially using the bounce velocity parameter and taking into account the stroke velocity of the actuator.

In a preferred embodiment of the invention, it is chacterized by; calculating the stroke velocities associated with each actuator’s bounce, pitch, and roll motions separately.

In a preferred embodiment of the invention, it is chacterized by; independently determining gain coefficients for bounce, pitch, and roll motions to control the actuator.

In a preferred embodiment of the invention, it is chacterized by; using a total of twelve controller functions to independently evaluate the bounce, pitch, and roll motions at each corner of the vehicle.

In a preferred embodiment of the invention, it is chacterized by; using three control functions for each corner, one for each of the bounce, pitch, and roll motions, to independently evaluate these motions at each corner.

In a preferred embodiment of the invention, it is chacterized by; the reference point for sensor is the vehicle's center of gravity.

The protection scope of the invention is specified in the claims and cannot be limited to the description made for illustrative purposes in this brief and detailed description. It is clear that a person skilled in the art can present similar embodiments in the light of the above descriptions without departing from the main theme of the invention.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 shows the drawing of a representative geometry.

The drawings do not necessarily need to be scaled and some details that are not necessary to understand the present invention may have been omitted. In addition, elements that are at least largely identical or at least largely have identical functions are indicated with the same number.

DESCRIPTION OF THE REFERENCES IN FIGURES

10. Actuator

20. Sensor

CB. Bounce actuator damping ratio

CR. Roll actuator damping ratio

CP. Pitch actuator damping ratio

COG. Central of gravity

DETAILED DESCRIPTION OF THE INVENTION

In this detailed description, the invention that suspension system control method for vehicles is described by means of examples only for clarifying the subject matter such that no limiting effect is created.

The drawings depict the axial movements of the sensor that preferably positioned at the center of gravity (COG) in the vehicle's geometry. The x-axis represents the axis forward to the front of the vehicle; the y-axis represents the axis toward the sides of the vehicle, and z represents the vertical axis. 0 represents the angular change that occurs in the roll condition, which is the rotation condition along the mentioned x-axis, and Q represents the angular change that occurs in the pitch condition, which is the angular change along the y-axis. Similarly, z _b , z ₀ and z _e represent the respective vectors. The corner reference point signifies at least one point which pre-defined in or near the corners of the vehicle. The mentioned axial representation is not limited to these descriptions but is indicated for the clear expression of the invention.

The invention relates a method to control the suspension system in vehicles using at least one controller to enabling the independent control of the actuators (10) associated with the vehicle's wheels; by calculating the vertical-axis motion changes occurring at each corner of the vehicle, measured either from the vehicle's center or any reference point, characterized by; to establish the geometric relationship between each corner and adjacent corner of the mentioned vehicle, the geometric relationship is established using the bounce, pitch, and roll motion data obtained from at least one sensor (20) expressed as a vector, between the mentioned sensor's (20) associated reference point and at least one reference point associated with the mentioned actuator (10); the control of the mentioned actuators (10) is achieved by determining in the vertical axis at least one of accelerations, or velocities of the bounce motion of each corner of the vehicle, along with at least one of the vertical positions, accelerations, or velocities of the pitch and roll angles.

The subject of the invention relates to a control method that enables the actuator (10), which is a suspension component of the vehicle, to dynamically respond to forces such as bounce, pitch, and roll during driving

Through the invention, the calculation of vertical motion, preferably occurring at the central of gravity (COG) or its vicinity, is performed. The impact of this motion on reference points at the corners is determined. Angular rotational motions caused by pitch and roll measured around the central of gravity (COG) or its vicinity are calculated by converting the relationships between reference points belonging to each of the two adjacent corners into linear (lineal) motion.

Figure 1 provides a representative geometry illustrating the operation of the invention. Within the scope of the invention, the vehicle is equipped with at least one sensor (20). The mentioned sensor (20) is a gyroscope that used for measuring the vehicle's bounce, pitch, and roll motions.

In the preferred embodiment of the invention, the mentioned sensor (20) is positioned on at least one reference point. In the preferred embodiment, the mentioned reference point is the central of gravity (COG) of the vehicle.

The purpose of the sensor (20) in the invention, as seen in Figure 1 , is to measure the displacements and/or velocities and/or accelerations and reaction forces of the bounce actuator damping ratio (CB), roll actuator damping ratio (CR), and pitch actuator damping ratio (CP), which are three virtual dampers positioned at each corner of the vehicle, with respect to the horizontal reference plane. In the preferred alternative embodiments of the invention, there are two gyroscopes and one accelerometer positioned at the central of gravity (COG).

Preferably, the bounce, pitch, and roll motions measured with at least one sensor (20) that located at or near the vehicle's center of gravity (COG) are distributed onto reference points associated with each actuator (10). Linear/lineal location and/or velocity and/or acceleration changes resulting from the pitch angle 0 and roll angle 0 of the mentioned reference points are determined based on the displacement difference in the z direction ( z _b ).

The displacement of each corner (quarter section where the wheel is located) in a four- wheeled vehicle is calculated as follows:

Z _s i = Z _s — L sin 0 + t sin 0 (1 )

Z _{s r} = Z _s — Lf sin 0 — tf sin 0 (2)

Z _{s ri} = Z _s + L _r sin 0 + t _r sin 0 (3)

Z _{s ri} = Z _s + L _r sin 0 — tf sin 0 (4)

The velocity of each corner (quarter section where the wheel is located) in a four- wheeled vehicle is calculated as follows:

Z _{s ri} = Z _s + L _r 0 cos 0 + t _r 0 cos 0 (7)

Z _{s rr} = Z _s + L _r 0 cos 0 — t _r 0 cos 0 (8)

Each equation, represents the calculation for the front left, front right, rear left, and rear right reference points (actuators) in order. L _f It represents the distance between the reference point where the sensor (20) is located and the reference point where the frontmounted actuator (10) is located, (vector distance)

L _r It represents the distance between the reference point where the sensor (20) is located and the reference point where the rearmounted actuator (10) is located, (vector distance) t _f It represents the distance between the reference points of the two actuators (10) on the front axle. t _r It represents the distance between the reference points of the two actuators (10) on the rear axle.

Z _s It represents the body velocity along the z-axis near the vehicle's center of gravity (COG). In the alternative configuration, it represents the velocity of the part (quarter) in the region where each actuator (10) is located.

Z _s It represents the body displacement along the z-axis near the vehicle's center of gravity (COG). In the alternative configuration, it represents the displacement of the part (quarter) in the region where each actuator (10) is located.

L _f and L _r represent the x-axis component of the vector between the measurement point of the sensor (20) and the coordinate to be measured. For simplification, the x-axis component is used. In cases where more precise calculations are required, the vector components in the y and z axes should also be taken into account tf ve t _r represent the y-axis component of the vector between the measurement point of the sensor (20) and the coordinate to be measured. For simplification, the y-axis component is used. In cases where more precise calculations are required, the vector components in the x and z axes should also be taken into account.

The body motions of the vehicle, which are roll, pitch, and bounce calculated at the center of gravity (COG), and the geometric relationship with the corners is determined through the equations mentioned above. This way, the body motions occurring at the corners of the vehicle, preferably in a car, are distributed vectorially from the center of gravity (COG). The invention involves calculating the displacement parameter associated with each actuator (10) vectorially by multiplying the sine of the pitch angle with the vector distance between the reference point where the sensor (20) is located and the reference point associated with the actuator (10), and by multiplying the sine of the roll angle with the vector distance between the two reference points associated with two actuators (10) on the same axis. Expressions illustrating the calculations are provided in Equations 1 -2-3- 4.

Similarly, the body velocity parameter associated with each actuator (10) is calculated vectorially by multiplying the cosine of the pitch angle with the vector distance between the reference point where the sensor (20) is located and the reference point associated with the actuator (10), and by multiplying the cosine of the roll angle with the vector distance between the two reference points associated with two actuators (10) on the same axis. Expressions illustrating the calculations are provided in Equations 5-6-7-8.

In alternative configurations of the invention, reference points other than the point where the sensor (20) is located can be used with following the necessary definitions. In alternative applications, similar calculations can be made using multiple sensors (20) and/or can be carried out with sensors (20) that located at multiple points

The selection of control coefficients within the scope of the invention is calculated with the equations:

The equations are used sequentially for bounce, roll, and pitch movements

^Bounce > CROII > Cpitch represent the upper limit independent coefficients, and C _min represents the lower limit independent coefficients. In the preferred embodiment of the invention, the calculation is performed by separating the stroke velocities and/or stroke and/or stroke accelerations related to the bounce, pitch, and roll movements of each actuator (10) from each other

In the preferred embodiment of the invention, the calculation is performed by separating the velocities and/or displacements and/or accelerations related to the bounce, pitch, and roll movements at each corner of the vehicle from each other/

The invention allows for a more effective suspension control by pre-determining the independent coefficients C (C _Bounce , C _Ro u, C _Pitch ) integrated with applications where the gain coefficients to be used in the calculations are previously estimated. In this regard, the coefficients are pre-determined, and each actuator (10) and/or damper can be brought to its optimum damping value/state. The coefficients can be determined or predicted based on road condition data obtained through environmental detection systems such as lidar/camera/GPS, or data from road conditions recorded in the cloud. Alternatively, steering angle, brake system, motor sensors, or electric motor or linear acceleration sensors can also be used.

In another preferred embodiment of the invention, at least one controller supported by artificial intelligence and/or machine learning is used to blend driving characteristics and environmental information, allowing the determination of optimum independent Coefficients

Through the invention, bounce, roll, and pitch motions can be prioritized over each other. In the preferred configuration, measurements can be performed with at least one, preferably two, gyroscopes and one accelerometer located on the center of gravity (COG). This eliminates the need for accelerometers at each corner. In alternative applications, different numbers of sensors (20) can be used in different regions.

In the alternative embodiment of the invention, measurements can be carried out using the sensors (20) included by the actuator (10).

In another preferred embodiment of the invention, sensors (20) can be positioned on the wheels or sprung mass