Method and system for implementing active suspension using independently actuated wheels

Abstract

A control system for controlling the motion of a vehicle with wheels is provided. The control system includes: a suspension unit configured to support the wheels, each driven by a throttle-controlled motor; a set of sensors configured to detect the motion of the vehicle, wherein the motion is represented by lift, pitch, and roll values; a distribution module connected to the sensors and configured to generate and send distributed throttle signals to the throttle to minimize motion by solving a motion-related optimization problem; and a motor control unit configured to drive each motor according to the distributed throttle signals.

Description

Technical Field

[0001] The present invention generally relates to a method for reducing chassis motion by using individual actuated wheels without the need to add actuators (i.e., active suspension). Background Technology

[0002] Active suspension is a type of vehicle suspension that reduces the movement of the vehicle chassis due to uneven road surfaces. Active suspension uses actuators that reconfigure the suspension in response to road surface changes. For example, active suspension can use linear motors to move the wheels up or down to reduce the impact of driving over potholes. Active suspension provides improved ride comfort but requires specialized actuator hardware, which can be expensive.

[0003] Anti-lift and anti-sag suspensions are various types of vehicle suspensions that reduce the movement of the vehicle chassis due to the vehicle's acceleration and / or deceleration. When a vehicle accelerates, inertia causes the vehicle to pitch, resulting in front-end lift and rear-end sink. For rear-wheel-drive vehicles, anti-sag suspensions use tilting suspension rods to redirect some of the traction generated by the rear wheels into vertical forces to counteract the rear-end sinking. Hence the name "anti-sag" suspension. For front-wheel-drive vehicles, anti-lift suspensions use tilting suspension rods to counteract the natural lift of the front end during acceleration. Hence the name "anti-lift" suspension. The anti-lift / sag characteristics of a suspension are a result of the geometry of the suspension design and require only standard (passive) hardware. Suspensions specifically designed for anti-lift / sag characteristics are common in commercial vehicles. Summary of the Invention

[0004] Some currently disclosed implementations are based on the understanding that future (e.g., electric) vehicles will employ (e.g., four) independent motors to drive each wheel independently, rather than a single motor / engine driving two or four wheels together. This invention can provide anti-lift / sag characteristics in the vehicle suspension and independently driven wheels to provide the effects of active suspension without any additional hardware (other than the individual motors that independently actuate each wheel). This invention is based on the understanding that when wheels are independently driven, vertical forces on the vehicle chassis can be manipulated by anti-lift / sag suspension forces. For example, when the front wheels enter a pothole, the vehicle driving over the pothole will initially pitch forward. This forward pitch can be counteracted by applying traction to the front wheels and braking force to the rear wheels by generating rearward pitch. When the rear wheels enter a pothole, the opposite force can be applied. By using existing hardware features in the vehicle suspension (anti-lift / sag) and another hardware feature predicted to be adopted in the future (independently driven wheels), this invention produces an improvement in driving comfort provided by active suspension, but without any additional hardware.

[0005] According to embodiments of this disclosure, a control system for controlling the motion of a vehicle having wheels is provided. The control system may include: a suspension unit configured to support the wheels, each driven by a motor controlled by a throttle; a set of sensors configured to detect (measure) the motion of the vehicle, wherein the motion is represented by lift, pitch, and roll values; an allocation module connected to the sensors, configured to generate / calculate and send allocated throttle signals to the throttle to minimize motion by solving a motion-related optimization problem; and a motor control unit configured to drive each motor via the throttle according to the allocated throttle signals.

[0006] Furthermore, some implementations may provide a method for controlling the motion of a vehicle with wheels. In this case, a suspension unit is configured to support the wheels, and the method includes driving the wheels respectively via motors controlled by a throttle; measuring the motion of the vehicle using a set of sensors, wherein the motion is represented by the vehicle's lift, pitch, and roll values; calculating and sending an assigned throttle signal to the throttle to minimize the motion by solving a motion-related optimization problem; and driving the individual motors via the throttle according to the assigned throttle signal.

[0007] The currently disclosed embodiments will be further explained with reference to the accompanying drawings. The drawings shown are not necessarily to scale, but the focus is generally on illustrating the principles of the currently disclosed embodiments. Attached Figure Description

[0008] [ Figure 1 ]

[0009] Figure 1 A diagram illustrating a definition for describing the motion of a vehicle according to an embodiment of the present disclosure is shown.

[0010] [ Figure 2 ]

[0011] Figure 2 An actuator control system according to an embodiment of the present disclosure is shown.

[0012] [ Figure 3A ]

[0013] Figure 3A A force analysis diagram of the front suspension of a vehicle according to an embodiment of the present disclosure is shown.

[0014] [ Figure 3B ]

[0015] Figure 3B A force analysis diagram of the front suspension of a vehicle according to an embodiment of the present disclosure is shown.

[0016] [ Figure 4A ]

[0017] Figure 4A A force analysis diagram of the rear suspension of a vehicle according to an embodiment of the present disclosure is shown.

[0018] [ Figure 4B ]

[0019] Figure 4B A force analysis diagram of the rear suspension of a vehicle according to an embodiment of the present disclosure is shown.

[0020] [ Figure 5 ]

[0021] Figure 5 This is a schematic diagram illustrating how traction distribution causes vehicle lifting, according to an embodiment of the present disclosure.

[0022] [ Figure 6 ]

[0023] Figure 6 This is a schematic diagram illustrating how traction distribution produces vehicle pitch according to embodiments of the present disclosure.

[0024] [ Figure 7 ]

[0025] Figure 7 An example of how traction distribution is performed according to an embodiment of the present disclosure to avoid chassis movement when driving on a bump in the road is shown.

[0026] [ Figure 8 ]

[0027] Figure 8 The diagram illustrates a traction distribution that results in lifting motion without any pitching, rolling, or yaw motion, according to an embodiment of this disclosure.

[0028] [ Figure 9 ]

[0029] Figure 9 The diagram illustrates a traction distribution that results in pitch motion without any lift, roll, or yaw motion according to an embodiment of the present disclosure.

[0030] [ Figure 10 ]

[0031] Figure 10 The diagram illustrates a traction distribution that results in rolling motion without any lifting, pitching, or yaw motion, according to an embodiment of the present disclosure.

[0032] [ Figure 11 ]

[0033] Figure 11The diagram illustrates a traction distribution that results in yaw motion without any lift, roll, or pitch motion according to an embodiment of the present disclosure.

[0034] [ Figure 12 ]

[0035] Figure 12 A block diagram of a throttle distribution system according to an embodiment of the present disclosure is shown.

[0036] [ Figure 13 ]

[0037] Figure 13 A block diagram illustrating a throttle distribution method according to an embodiment of the present disclosure is shown.

[0038] [ Figure 14A ]

[0039] Figure 14A This is a diagram illustrating an actuator control method for a vehicle according to an embodiment of the present disclosure.

[0040] [ Figure 14B ]

[0041] Figure 14B This is a diagram illustrating an actuator control method for a vehicle according to an embodiment of the present disclosure.

[0042] As noted in the discussion, while the above figures illustrate the currently disclosed embodiments, other embodiments are conceived. This disclosure presents illustrative embodiments by way of representation and not limitation. Many other modifications and embodiments falling within the scope and spirit of the principles of the currently disclosed embodiments will be apparent to those skilled in the art. Detailed Implementation

[0043] The following description provides only exemplary embodiments and is not intended to limit the scope, applicability, or configuration of this disclosure. Rather, the following description of the exemplary embodiments will provide those skilled in the art with an implementation description of one or more exemplary embodiments. Various changes may be made in terms of the function and arrangement of the elements without departing from the spirit and scope of the subject matter disclosed in the appended claims.

[0044] Specific details are set forth in the following description to provide a thorough understanding of the embodiments. However, those skilled in the art will understand that these embodiments can be practiced without these specific details. For example, systems, processes, and other elements in the disclosed subject matter may be shown as components in block diagram form to avoid obscuring the embodiments with unnecessary details. In other instances, well-known processes, structures, and techniques may be shown without unnecessary details to avoid obscuring the embodiments. Furthermore, the same reference numerals and names in the various figures indicate the same elements.

[0045] Similarly, various implementations can be described as processes, which are described as flowcharts, data flow diagrams, structural diagrams, or block diagrams. Although a flowchart can describe operations as sequential processes, many operations can be performed in parallel or simultaneously. Furthermore, the order of operations can be rearranged. When an operation completes, the process may terminate, but may have other steps not discussed or included in the accompanying drawings. Moreover, not all operations in all specifically described processes occur in all implementations. A process may correspond to a method, function, procedure, subroutine, subroutine, etc. When a process corresponds to a function, the termination of the function may correspond to the function returning to the calling function or the main function.

[0046] Furthermore, implementations of the disclosed subject matter can be carried out, at least partially manually or automatically. This can be performed, or at least assisted by, the use of machines, hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof, either manually or automatically. When implemented in software, firmware, middleware, or microcode, program code or code segments that perform the necessary tasks can be stored in a machine-readable medium. The processor can then perform the necessary tasks.

[0047] Implementation of this disclosure

[0048] Figure 1 An example of a vehicle 100 (e.g., an automobile) is shown, with "vehicle" being included to define the terminology used in this disclosure. Vehicle 100 may include at least four wheels (not shown) attached to the chassis via a suspension system. In the figures, three axes (x-axis, y-axis, and z-axis) are shown to illustrate rotation of vehicle 100 about the respective axes (102, 103, 104).

[0049] The x-axis 101 attached to the vehicle's coordinate system is called the longitudinal direction. Longitudinal motion includes the chassis's position, velocity, acceleration, and vibrations in this direction. The chassis's rotation 104 around the x-axis 101 is called rolling. Rolling motion includes the chassis's angle, angular velocity, and angular acceleration in this direction.

[0050] The y-axis 102 attached to the vehicle's coordinate system is called the lateral direction. Lateral motion includes the chassis's position, velocity, acceleration, and bumps in this direction. The chassis's rotation 105 around the y-axis 102 is called pitch. Pitch motion includes the chassis's angle, angular velocity, and angular acceleration in this direction.

[0051] The z-axis 103, attached to the vehicle's coordinate frame, is called the lifting direction. Lifting motion includes the chassis's position, velocity, acceleration, and vibration in this direction. The chassis's rotation 106 around the z-axis 103 is called yaw. Yaw motion includes the chassis's angle, angular velocity, and angular acceleration in this direction.

[0052] According to embodiments of the present invention, passenger comfort can be improved by reducing the movement of the vehicle chassis. For example, in an autonomous vehicle, passengers may want to read during their commute, but unwanted chassis movement could cause motion sickness.

[0053] However, it is important that this invention does not eliminate all chassis motion, because the purpose of a vehicle is to move the chassis (and its contents) between positions. There are two main factors contributing to vehicle chassis motion: the vehicle's drive mechanism and the quality of the road surface the vehicle travels on. This invention reduces chassis motion due to road roughness without changing the vehicle's drive mechanism. Instead, one of the features of this invention is that it maintains the vehicle's drivability. Drivability means that the vehicle responds to the driver's (human or autonomous) commands in a predictable and repeatable manner. After all, the simplest way to eliminate bumps is to stop the vehicle, but that is not the right solution. Crucially, this invention maintains drivability so that the driver can safely and usably operate the vehicle.

[0054] The driver controls the movement of the vehicle (and its chassis) in the longitudinal and yaw directions. The gas / brake pedal controls longitudinal acceleration (and thus speed and position), and the steering wheel controls the yaw rate (and thus the yaw direction). To improve comfort, the invention distributes traction to each wheel and sets the steering angle to achieve the driver-specified acceleration and yaw rate while reducing chassis movement in the lift, pitch, and roll directions. Therefore, in this disclosure, comfort is synonymous with the lift, pitch, and roll movements of the chassis. According to the invention, the lift, pitch, and roll movements of the chassis can be reduced without sacrificing driving performance, because the invention is only applicable to vehicles with independently actuated wheels, providing three additional degrees of freedom while maintaining driving performance; that is, for vehicles with independently driven wheels, there are four “throttles” instead of one. The invention can also reduce lateral movement of the vehicle, which depends on tire slippage to reduce wear on the vehicle's tires.

[0055] Figure 2An actuator control system 200 arranged in a vehicle 100 according to an embodiment of the present disclosure is shown. The actuator control system 200 may include an input / output interface (I / O) 210 connected to a vehicle sensor 1201 and a road roughness sensor 1302, one or more processors 220, and a memory device 230 storing a program implemented by a computer (processor), the computer-implemented program including a road roughness prediction program 231, an actuator control program 232, and a throttle distributor program 233.

[0056] Interface 210 is configured to form a wired network or a wireless network for the vehicle 100, and to perform data communication between the actuator control system 200 of the vehicle 100's wheels, vehicle sensor 1201, road roughness sensor 1302, and motors 1-4. Processor 220 is configured to execute a road roughness prediction program 231, an actuator control program 232, and a throttle distributor program 233 in response to sensor data from vehicle sensor 1201 and road roughness sensor 1302 via interface 210. Furthermore, processor 220 is configured to send control data to actuator controller 1402 via interface 210 when executing the road roughness prediction program 231, actuator control program 232, and throttle distributor program 233 in response to signals (data) from vehicle sensor 1201 and road roughness sensor 1302. The actuator controller 1402 performs throttle distribution to the motors 1-4 and steering control of the vehicle 100 based on control data regarding throttle distribution to each of the motors 1-4 and steering control from the processor 220.

[0057] The memory device 230 may be one or more memory units, which may include one or a combination of random access memory (RAM), read-only memory (ROM), non-volatile memory, and hard disk drive. Furthermore, the system 200 may include an actuator controller 1402 configured to receive output data (signals) from the processor 220 via interface 210, and based on the received output data signals, perform steering and throttle / brake control on each of the four motors 1-4 using wheel throttle / brake controllers (torque distribution modules) 1203 (1203-1, 1203-2, 1203-3, and 1203-4).

[0058] According to the present invention, the actuator control system 200 can distribute traction force to each wheel and set the steering angle to reduce chassis motion due to road roughness while maintaining driving performance. In one embodiment of the invention, road roughness is measured by a road roughness sensor 1302, and these measurements are used to calculate the traction force and steering angle of the vehicle 100. In another embodiment of the invention, road roughness is not measured, but is measured using a sensor 1201 on the vehicle 100 (vehicle motion sensor 1201) or an external sensor (not shown) arranged on / in the vehicle communicating with the actuator control system 200. In this embodiment, the motion sensor 1201 is used to calculate the traction force and steering angle of the vehicle 100. Another embodiment of the invention uses measurements of both road roughness and chassis motion using the vehicle motion sensor 1201 and the road roughness sensor 1302 to calculate the traction force and steering angle that reduce chassis motion and maintain driving performance.

[0059] According to some embodiments of the invention, wheeled vehicles (e.g., automobiles) having at least four independently actuated wheels arranged to motors 1-4 can be processed. In this case, each actuated wheel is configured to independently control the throttle and braking force generated by the respective wheel.

[0060] This invention can also be applied to vehicles with more than four independently actuated wheels or four sets of independently actuated wheels. For example, independent actuation can be achieved by using "hub motors" located in each wheel, but this invention can also be applied when the motors are located outside the wheels.

[0061] Conventional vehicles have two actuators for driving the vehicle: (1) the accelerator / brake and (2) the steering angle of, for example, the front tires. These actuators are used to follow the desired acceleration and yaw rate specified by the driver (who may be a human or an autonomous driving system). For a human driver, the desired acceleration and yaw rate are specified by the position of the gas / brake pedal and the steering wheel angle. For an autonomous driver, the desired acceleration and yaw rate are specified by a different method. Note that conventional vehicles have two actuators used to achieve two driving objectives (i.e., accelerator / brake and steering wheel) by tracking the desired acceleration and yaw rate.

[0062] The embodiments of the present invention are based on the understanding that a vehicle with independent throttle / brake wheels has three degrees of freedom, namely, four throttle / brakes and one steering angle. It is further recognized that these additional degrees of freedom can be used to improve passenger comfort by reducing the lifting, pitching, and rolling motions of the vehicle chassis.

[0063] It should be noted that the effects of the throttle / brake and steering angle on the lifting, pitching, and rolling motions of the vehicle chassis are not readily apparent. Some embodiments of the present invention are based on the understanding that the design of the vehicle suspension results in longitudinal and lateral forces generated by the wheels producing vertical forces on the chassis. Therefore, the relevant characteristics of the vehicle suspension will be discussed below.

[0064] Figure 3A and Figure 3B A rear-arm front suspension is shown. It is well known that other suspension designs are dynamically equivalent to rear-arm suspensions; therefore, for simplicity, even though some embodiments of the invention are applicable to other suspension designs, we will focus our discussion on this type of suspension. The key feature of a rear-arm suspension is the suspension arm that rotates about a pivot. Therefore, the wheel cannot move horizontally (i.e., in the longitudinal or lateral direction) nor vertically due to the rotation of the suspension arm.

[0065] Figure 3A and Figure 3B The forces on the front suspension are shown, along with a force analysis diagram of the front suspension. The front suspension applies four types of forces to the vehicle chassis (a for the left force and b for the right force):

[0066] Longitudinal reaction forces 303a and 303b: The left and right tires must generate driving forces 301a and 301b to accelerate / decelerate the vehicle. The suspension transmits these driving forces 301a and 301b to the vehicle chassis and generates longitudinal forces 303a and 303b.

[0067] Lateral reaction forces 305a and 305b: When the vehicle turns (i.e., the wheels grip the road), the left and right tires generate sliding forces 309a and 309b, respectively. The suspension transmits these tire sliding forces 309a and 309b to the chassis, generating lateral forces 305a and 305b, respectively.

[0068] Spring damping forces 308a and 308b: The deformation of the springs and the movement of the dampers in the suspension generate forces 308a and 308b on the chassis. The deformation / movement of the springs / dampers is caused by the movement of the vehicle chassis relative to the road or by the "movement" of the road height relative to the vehicle (i.e., the vehicle is traveling on a ridge). The spring-damper forces reduce the relative chassis-road movement and restore it to its default position (i.e., the chassis is flat relative to the road).

[0069] Vertical reaction forces 304a and 304b: Due to the inclined nature of the cantilever, 302a / b and 310a / b, longitudinal forces 303a / b and lateral forces 305a / b generate torque on the cantilever. In a stationary state, this torque is balanced by the vertical reaction forces 304a / b. Applying throttle force 302a / b to one of the front wheels results in a negative vertical reaction force 304a / b on the suspension. Since Figure 3 shows the front suspension, these vertical reaction forces 304a / b are anti-lift forces that prevent the front end of the vehicle from lifting during acceleration. Some embodiments of the invention are based on the understanding that, since these vertical reaction forces 304a / b depend on the actuation drive force 303a / b, they can be manipulated to control the lifting, pitching, and rolling movements of the chassis.

[0070] Figure 4A and Figure 4B A force analysis diagram of one of the rear suspension components is shown. Similar to the front suspension components, we can deduce how the throttle force on the rear wheels generates a positive vertical reaction force on the vehicle suspension. This force is called the anti-sag force because it prevents the rear end of the vehicle from "power-sag" during acceleration.

[0071] The actuator control system 200 can use these anti-lift and anti-sinking forces to manipulate the movement of the vehicle chassis. For example, Figure 5 This illustrates how throttle / brake forces applied to the front and rear wheels affect vehicle lift. Arrows 501 and 502 represent the driving forces generated by the front and rear tires, respectively. For simplicity, due to... Figure 5 Only the vehicle's motion in the pitch plane is shown, therefore, Figure 5 The forces on the left and right front tires are the same, and the forces on the left and right rear tires are also the same. In practice, for 3D control of chassis movement, it is necessary to apply different forces to the left and right sides of the vehicle. Traction forces 501 and 502 are in opposite directions, i.e., the front wheels accelerate while the rear wheels brake. This causes the wheels to rotate from default positions 503 and 504 to positions 505 and 506 respectively. As shown in the diagram, this causes the chassis 507 to drop (move in the negative lift direction).

[0072] Figure 6 This illustrates another example of lift and pitch motion in the pitch plane. Figure 6 In this configuration, the same traction forces 601 and 602 are applied to the front and rear wheels. The front wheels rotate forward from the default position 603 to 605, and the rear wheels rotate backward from the default position 604 to 606. This causes the chassis 607 to pitch forward, as shown in the diagram. Note that this forward pitch is the opposite of the natural backward pitch that occurs when the vehicle accelerates. This is called the anti-pitch effect.

[0073] Similar effects occur in three dimensions (i.e., not limited to the pitch plane). However, vehicle dynamics are more complex because throttle / braking force is no longer the only force acting on the tires. Instead, we must now consider the sliding force of the tires moving laterally. However, models relating throttle / braking force and steering angle to the chassis's lift, pitch, and roll motions can be derived. For example,

[0074]

[0075]

[0076]

[0077]

[0078]

[0079] The spring damping force is given by the following:

[0080]

[0081] We can use a model that correlates throttle / brake force and steering angle with the chassis's lift, pitch, and roll motions for design. However, this model is unnecessary for implementation, and the model itself is not required (1). In fact, a more accurate physics-based model or machine learning model can replace model (1). The variables of the model are summarized in Tables 1 and 2.

[0082] [Table 1]

[0083]

[0084] [Table 2]

[0085] <![CDATA[b f ,b r ]]> Front / Rear Wheelbase: The longitudinal distance from the vehicle's center (CG) to the front / rear tires. <![CDATA[L f ,L r ]]> Front / rear track width: The lateral distance between the left and right wheel fingers at the front and rear of the vehicle. <![CDATA[M s ]]> chassis quality <![CDATA[J X ,J Y ,J Z ]]> The chassis' moments of inertia about the x, y, and z directions (i.e., roll, pitch, and yaw moments of inertia). <![CDATA[K ij ,C ij ]]> Spring stiffness and damping ratio of each suspension component

[0086] Using model (1), the distribution of throttle / brake force and steering angle can be determined, and these distributions produce something similar to Figure 5 and Figure 6 The three-dimensional motion shown.

[0087] Figure 8 An example of throttle / brake force distribution is shown, which raises the chassis without any pitch, roll, or yaw motion. The left and right rear tires each have positive (i.e., throttle) forces 801 and 802 that cause the rear end to lift due to anti-lifting forces. The left and right front tires have negative (i.e., braking) forces 803 and 804 that cause the front end of the vehicle to lift, because the resulting anti-lifting force is negative. This force pattern is similar to... Figure 5Similar. The relative magnitudes of forces 801-804 depend on the values ​​of the model parameters.

[0088] Figure 9 An example of throttle / brake force distribution is shown, which causes chassis pitch without any lift, roll, or yaw motion. All tires have force 901-904 in the same direction, which will cause the vehicle to pitch rearward. This force pattern is similar to... Figure 6 Similar. The relative amplitudes of forces 901-904 depend on the values ​​of the model parameters.

[0089] Figure 10 An example of throttle / brake force distribution is shown, which causes the chassis to roll without any lift, pitch, or yaw movement. The tires on the right side of the vehicle are aligned with... Figure 5 The same pattern generates forces 1002 and 1004, causing the right side of the vehicle to drop (i.e., move in the negative lift direction). The tires on the left side of the vehicle move in conjunction with... Figure 5 The opposite pattern generates forces 1001 and 1003, causing the left side of the vehicle to lift. The end result is that the vehicle's center of gravity remains stationary while it rolls. The relative magnitudes of forces 1001-1004 depend on the values ​​of the model parameters.

[0090] Figure 11 An example of throttle / brake force distribution is shown, which causes the vehicle to yaw without any lift, pitch, or roll. This force distribution is more complex because yaw / turning the vehicle generates a centripetal force, which in turn causes the vehicle to roll. This roll must then be compensated for. Forces 1101-1104 cause yaw by applying differential forces to the left and right sides of the vehicle (i.e., forces 1101 and 1103 are positive on the left side, while forces 1102 and 1104 are negative on the right side). The resulting yaw causes the vehicle to roll. Figure 10 Applying forces 1001-1004 cancels the rolling motion. Adding these forces (1101+1001, 1102+1002, 1103+1003, 1104+1004) generates forces 1105 and 1106. In this distribution, differential driving forces are applied to the left rear tire 1105 and the right rear tire 1106, but no force is applied to the front tires. This causes the vehicle to turn without rolling. In reality, the relative magnitudes of forces 1001-1004 and 1101-1106 depend on the values ​​of the model parameters.

[0091] Furthermore, some embodiments of the present invention are based on the understanding that, Figures 8 to 11 The relationship between the vehicle's steering angle and lift, pitch, roll, and yaw motions and throttle / brake force can be used to improve passenger comfort. One embodiment of the invention... Figure 12 As shown in the figure. In this embodiment, system 200 may include three modules that work together to improve passenger comfort; a sensor module 1201 that measures (or estimates) the motion of the chassis; a torque distribution module 1203 that uses model (1) to calculate the desired distribution of driving force; and (at least) four throttle / brake controllers (torque distribution modules) 1203 that apply the desired traction force to each wheel. The sensor module 1201 may include (but is not limited to) inertial measurements using gravity sensors, accelerometers, GPS, etc. The throttle distribution (torque distribution) module 1202 calculates the throttle / brake setpoint of the motor / brake controller based on the measurement of chassis motion and knowledge of how throttle / brake force affects chassis motion (i.e., model (1)). This module may be, for example, a computer processor, analog circuitry, or mechanical linkage. For example, as an illustrative example, the torque distribution module may include a digital computer processor that executes an optimization algorithm that calculates the throttle / brake distribution, which can minimize chassis motion in real time. Another illustrative example: The torque distribution module 1202 may include analog circuitry that implements H ∞ The gain of the state feedback controller (designed using (1)) minimizes the integrated RMS response of chassis motion to the integrated RMS roughness of the road.

[0092] Another embodiment of the present invention is in Figure 13 As shown in the diagram, the actuator control system 200 may include an additional module 1301 that predicts the future impact of road roughness on chassis motion. Module 1301 includes two sub-modules: a sensor sub-module 1302 and a predictor sub-module 1303. The sensor sub-module 1302 senses the road ahead of the vehicle. Sub-module 1302 may include, for example, a camera, radar, or lidar (light detection and ranging), or sonar measuring the road surface ahead of the vehicle. The predictor sub-module 1303 predicts when these road bumps will reach each tire of the vehicle and their impact on the vehicle. For example, the predictor sub-module 1303 may include a simple model that uses the vehicle's current speed and the distance to the bump to determine when the bump will pass under each tire. The torque distribution module 1202 can be modified to use this predictive information to further improve passenger comfort. For example, if the torque distribution module includes a computer processor that performs optimization algorithms, the predicted road roughness can be included in the optimization problem to improve the bumps.

[0093] Figure 7 An example of how the actuator control system 200 uses predictive information to improve a bulge is shown. Figure 7Four snapshots are shown of a vehicle encountering a bump 701 on the road. In the first snapshot, the vehicle is approaching the bump 701. The actuator control system 200 applies throttle 702 to the front tires, causing them to lift 703 above the bump 701. In the next snapshot, the actuator control system 200 stops the throttle, causing the front wheels to return to ground height 704 after passing the bump 701. In the third snapshot, the actuator control system 200 applies braking force 705 to the rear tires, lifting the tires 706 above the bump 701. Finally, the braking force is released, allowing the rear tires to return to their original position 707 after passing the bump 701.

[0094] Figure 14 illustrates how the actuator control system 200 can be modified via the vehicle's control / software stack. The current stack can comprise two layers: a driver 1401 (human or autonomous) and a low-level actuator controller 1402. Currently, the driver 1401 (human or autonomous) uses the gas / brake pedal and steering wheel to indicate desired acceleration / deceleration and steering / yaw rates, and the actuator controller 1402 implements these desired behaviors. Note that in older vehicles, the low-level actuator controller 1402 may be a simple feed-through controller, i.e., the driver directly controls the throttle via cables, brakes via cylinders, and steering angles via mechanical links. In modern vehicles, low-level actuator controllers are generally more intelligent. However, the actuator control system 200 according to the invention is compatible with any type of low-level actuator controller.

[0095] The actuator control system 200 according to the invention can add a new controller layer 1403 between the driver and the actuator controller. The new controller layer 1403 is a torque distribution module that determines the setpoints of the individual actuators to maintain the driver's desired driving characteristics (i.e., achieving the desired acceleration and yaw / cornering) while improving passenger comfort. These additional benefits can be provided according to some embodiments of the invention because it is applicable to vehicles with independently actuated throttle / brakes for each wheel. Therefore, three additional degrees of freedom exist to achieve the desired driving configuration. The torque distribution module uses these additional degrees of freedom to improve passenger comfort.

[0096] Furthermore, the various methods or processes outlined herein may be encoded as software that can be executed on one or more processors employing any of a variety of operating systems or platforms. Moreover, such software can be written using any of many suitable programming languages ​​and / or programming or scripting tools, and it can also be compiled into executable machine language code or intermediate code that executes on a framework or virtual machine. Typically, the functionality of program modules can be combined or distributed across different implementations as needed.

[0097] Furthermore, embodiments of this disclosure can be embodied as a method, and examples of such methods are provided. Actions performed as part of this method can be ordered in any suitable manner. Therefore, embodiments in which actions are performed in a different order than those shown may be constructed, which may include performing certain actions simultaneously, even if they are shown as sequential actions in the illustrative embodiments. Moreover, the use of sequential terms (such as first, second) in a claim to modify a claim element does not in itself imply any priority, precedence, or order of one claim element relative to another claim element, or the temporal order of the actions of the method, but is merely used to distinguish one claim element with a specific name from another element with the same name (but for the purpose of using sequential terms) to differentiate claim elements.

[0098] Although certain preferred embodiments have been described with reference to them, it should be understood that various other changes and modifications may be made within the spirit and scope of this disclosure. Therefore, the claims are intended to cover all such changes and modifications that fall within the true spirit and scope of this disclosure.

Claims

1. A control system for controlling the motion of a vehicle having wheels, the control system comprising: A suspension unit configured to support wheels, each of which is driven by a throttle-controlled motor; A set of sensors configured to detect the motion of the vehicle, wherein the motion is represented by the vehicle's lift, pitch, and roll values; Road roughness sensor; An input / output interface, which is connected to the set of sensors and the road roughness sensor; One or more processors; A memory device that stores computer-implemented programs, including road roughness prediction programs, actuator control programs, and throttle distributor programs; A distribution module, implemented by one or more processors executing the throttle distributor program, is connected to the sensor and configured to generate and send the distributed throttle signal to the throttle to minimize chassis motion in real time by executing an optimization algorithm that calculates throttle / brake distribution, thereby solving motion-related optimization problems and minimizing motion. A motor control unit configured to drive each motor via the throttle according to an assigned throttle signal. The road roughness measured by the road roughness sensor is used to calculate the traction force allocated to each wheel and the vehicle's steering angle, reducing chassis movement caused by road roughness and maintaining driving performance.

2. The control system according to claim 1, wherein, The assigned throttle signal drives the motor to change the distance between the front and rear wheels in response to detected motion.

3. The control system according to claim 1, wherein, The assigned throttle signal drives the motor to move the right wheel closer together and the left wheel further away in response to the detected rolling motion in the opposite direction, thereby generating the rolling motion.

4. The control system according to claim 1, wherein, The sensor is a camera.

5. The control system according to claim 1, wherein, The sensor is an angle sensor.

6. The control system according to claim 1, wherein, The sensor is a combination of a camera and an angle sensor.

7. The control system according to claim 1, wherein, The suspension unit includes a torsion bar suspension.

8. A method for controlling the movement of a vehicle having wheels and a suspension unit, the suspension unit being configured to support the wheels, the method comprising the steps of: The wheels are driven individually by motors controlled by a throttle. The motion of the vehicle is measured using a set of sensors, wherein the motion is represented by the vehicle's lift, pitch, and roll values; Calculate the assigned throttle signal and send the assigned throttle signal to the assigned throttle, thereby solving an optimization problem related to the motion and minimizing the motion by executing an optimization algorithm that calculates the throttle / brake allocation in real time; and Based on the assigned throttle signal, each motor is driven via the throttle. The road roughness measured by a road roughness sensor is used to calculate the traction force allocated to each wheel and the vehicle's steering angle, thereby reducing chassis movement caused by road roughness and maintaining driving performance.

9. The method according to claim 8, wherein, The assigned throttle signal drives the motor to change the distance between the front and rear wheels in response to detected motion.

10. The method according to claim 8, wherein, The assigned throttle signal drives the motor to move the right wheel closer together and the left wheel further away in response to the detected rolling motion in the opposite direction, thereby generating the rolling motion.

11. The method according to claim 8, wherein, The sensor is a camera.

12. The method according to claim 8, wherein, The sensor is an angle sensor.

13. The method according to claim 8, wherein, The sensor is a combination of a camera and an angle sensor.

14. The method according to claim 8, wherein, The suspension unit includes a torsion bar suspension.

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