Protected system of active suspension

In accordance with §119 (e) (1) of section 35 of the Laws of the United States, this application claims priority to provisional application №60 / 733 960 US patent, entitled «SECURE ACTIVE SUSPENSION SYSTEM», filed November 4, 2005

TECHNICAL FIELD OF THE INVENTION

This invention relates to active suspension systems, such as those used in automobiles.

BACKGROUND

The automotive active suspension system used actuators, connected between the wheels of the car and the car body, continuous traffic control wheels relative to the vehicle body when the wheels are exposed to changing road conditions and driving conditions. Due to the ongoing correction of position, velocity and / or acceleration of the wheels in response to changing road conditions and driving conditions, active suspension system ensures excellent maneuvering capabilities, the feeling of the road, the sensitivity and security compared to traditional passive suspension.

Disclosure of invention

In one aspect, the invention is characterized by the fact that it proposed active suspension system in which some or all of the data involved in the exchange of information between system components (e.g., control commands sent from the controller to an actuator) is encrypted.

In yet another aspect, the invention is characterized by the fact that it proposed active suspension system for a vehicle, which includes a first component (e.g., a controller element), configured to communication with a second component (e.g., node actuator) using a network of any known topology (e.g., such as "tire," "ring", "Point to Point", etc.). The configuration of the first component provides encryption of at least some of the data (e.g., control commands) it transmits to the second component.

Embodiments may include one or more features described below. The configuration of the second component may provide the decryption and encryption algorithm can be used to encrypt the private (or secret) key and algorithm for public-key encryption.

The second component may be a linear actuator and may include motion sensors of parameters (e.g., position, velocity, acceleration) that provide feedback on the motion information with the first component (e.g., the controller). The traffic information feedback that is provided with the first component may also be encrypted.

In yet another aspect, the invention is characterized by the fact that it proposed active suspension system for a vehicle, which includes a first actuator which comprises a stator connected to the vehicle body, and an armature connected to a first wheel of a vehicle, and a controller configured to issue control commands to the first actuator using a network. The configuration of the controller encrypts control commands to the control commands to the first actuator.

In yet another aspect, the invention is characterized in that there is provided a method for managing encryption keys for the active suspension system, manufactured in mass production, wherein each active suspension system, manufactured in mass production, includes one or more components that need a key encryption. The method involves the use of a first encryption key for a first set of suspension system components, using a second encryption key for the second set of suspension system components, and maintaining a database for tracking encryption keys that are used in said first and second sets of components.

Embodiments may include one or more of the following. The first encryption key can be used for the components of the suspension system, provided for the first manufacturer of cars, the first brand of vehicles or the first car models, and the second encryption key can be used for the components of the suspension system, provided for the second manufacturer of cars, the second brand of cars or second model cars. Similarly, the first encryption key can be used for a first number of suspension systems components supplied for the first period and the second encryption key can be used for a second number suspension system components supplied for a second time period.

BRIEF DESCRIPTION OF DRAWINGS

In each of Figures 1-3 are block diagrams showing a top view of a vehicle with active suspension system.

EMBODIMENTS

Referring to Figure 1, note that the vehicle 10 includes an active suspension system 12, such as an active suspension system described in U.S. Patent №4,981,309 called «Electromechanical Transducing Along a Path», the complete disclosure of which is incorporated herein by reference. The active suspension system 12 includes four linear actuators 14a-14d, each of which is mechanically connected to one of the wheels 16a-16b of the vehicle. In some embodiments, the actuators are linear motors that include a stator mounted to the vehicle body, and a movable armature which is mounted on the wheel. In various locations near each wheel (or elsewhere in the vehicle) are arranged sensors for measuring the absolute or relative (with respect to the vehicle body) displacement, velocity and / or acceleration of the wheel. Typically, the measured vertical component of displacement, velocity and / or acceleration of the wheel, more sophisticated control systems may require vehicle motion measuring parameters also for other axes. To measure the motion parameters on the car body can be placed corresponding sensors.

The active suspension system 12 also includes a central controller 18 which is adapted to communicate with each of the four actuators 19 via the bus data, such as optical or electrical bus ™ FlexRay, MOST bus, or via another known tire technology.

When the vehicle 10 moves along the road surface, the central controller receives motion information (such as acceleration signals) from each of the sensors and sends control commands to each of the four actuators 14a-14d. Control commands cause the actuators to issue-driven efforts, which in turn causes the body of the car to respond as desired on the impact of the road. For example, the controller may issue commands to actuators minimize the vertical acceleration of the vehicle body when the vehicle wheels are moving over uneven surfaces (e.g. potholes surface road embankment, etc.) or when the vehicle is turning maneuver.

The actuators in the conventional active suspension system of a vehicle adapted to the development efforts of significant value to maintain control when driving the car body when the wheel of a car moving on uneven surfaces or when the vehicle is turning maneuver. Since the actuators are capable of such an effort, they can be controlled, causing the car to perform dangerous maneuvers. For example, in some embodiments, the actuators are powerful enough to cause some or all of the wheels to lose contact with the road surface when the vehicle is stopped or moving it to a flat road surface. This drive creates problems of safety for the people inside and outside the car, and therefore it can not have the functionality desired for a vehicle, produced on an industrial scale. Although the controller, which comes in the active suspension system, a commercially available, can not be programmed with the help of the program sequence of the fact causing the car to "jump" or engage in other dangerous maneuvers, there is a risk that people will be able to reprogram the controller or install other controllers, guaranteeing the functionality.

To prevent unsafe or unwanted active suspension control system, the proposed active suspension system encrypts the control commands and other information exchanged between system components. For example, as shown in Figure 2, the active suspension system 20 for a vehicle 21 includes a controller 22 associated with each of the four actuators 24a-24d of the wheels via the network 26. Controller 22, and each actuator 24a-24d has 30a-30e, interface data, transmitting and receiving data, such as control commands and feedback information from the sensors via the network 26. Each interface 30a-30e includes a data module 32a-32e and an encryption module 34a-34e decryption ensures secure communication between the controller and the actuator. In addition, each actuator includes a local controller 36a-36d, operatively connected to a motor 38a-38d, to execute commands sent by the central controller with the aim of driving the respective wheels 39a-39d. In one embodiment, the sensors 40a-40d motion parameters measured acceleration in the vertical direction and the acceleration data is fed back to the controller 22 via network 26. In some embodiments, the data interface, local controller, and other electronic components of the actuators placed in the casing of the motor stator to protect the electronic actuator unit against road conditions.

The modules 32a-32e encrypt encrypted data (e.g., control commands and acceleration data) prior to sending them over a network. When a system component, such as one of the actuators, receives the encrypted data, it decrypts the data using its module 34a-34e decryption. By encrypting the data exchanged between system components, reducing the risk management system of the replacement algorithm.

Encryption and decryption modules may be implemented in hardware, software, or a combination thereof, and these modules may use any known encryption algorithms, including private key encryption or public key encryption. Network 26 through which the exchange of data between components of the system may be a network of any known topology (e.g., such as "two-point communication", "rail", "star", "ring", and so on), and this network You may use any suitable protocol synchronous or asynchronous transfer.

For example, the network 26 shown in Figure 2, may comprise a FlexRay optical fiber bus, in which transfer FlexRay protocol is used, which is currently determined FlexRay consortium (www.flexray.corn) as follows.

ZagolovokPoleznaya nagruzkaZavershayuschaya part (5 bytes) (0-256 bytes) (3 bytes)

Payload packet FlexRay, containing the data that must be transferred between the system components, can be encrypted with a secret key common to a group of components, or a public key component in which data is sent.

In the active suspension system, which uses an encryption algorithm with the private key, each of the components (e.g., the controller and actuators) use the same secret key to encrypt and decrypt data. In case the encryption algorithm with the private key, for example, in accordance with data encryption standard (DES), it requires a system for managing the secret key (secret key) used (used) in the active suspension systems manufactured in mass production.

Key management can be done in many ways. For example, a supplier company active suspension system can use a single secret key for all components manufactured by this firm-supplier. However, if the private key is common to a group of components, is disclosed, it jeopardized the integrity of all suspension systems manufactured by that firm-supplier.

To reduce the damage caused by the disclosure of the secret key supplier company may use different secret keys for the components of active suspension, supplied by different companies-manufacturers of cars (for example, one key for cars Concern General Motors, and the second key - car group Ford), or different keys for different brands (for example, one key for cars of Chevrolet concern General Motors, and the second key - Car Cadillac's concern General Motors), various models (for example, one key for the car brand Cadillac model STS, and the second key - car model Cadillac's Escalade) or specific vehicles for personal use. Company-provider may periodically change the secret keys that are embedded in the active suspension system. For example, the supplier company may use a single secret key in year 1 and then move to the second secret key in the year 2. Alternatively supplier company can modify the secret keys after a certain number of manufacturing units (for example, the components of the first 1,000 active suspension systems, manufactured by the company the providing include a private key and the components of these systems 1,000 active suspension have another secret key, etc.).

For firm-supplier could replace broken or defective components, the firm-supplier preferably maintains a secure database, which tracked the secret keys used in components of active suspension, that sold by the vendor. For example, if the firm-supplier changes secret keys after production of every 1,000 active suspension systems, then that supplier firms have to maintain a database that correlates the private keys with ranges of serial numbers of components. If a component is broken or refused, the firm-supplier will be able to use the database for the key that was used in a particular active suspension system, and provide a new component (eg, a new actuator) proper private key.

In some embodiments, the use of company-supplier of active suspension could use encryption algorithm with a public key. In the case of public-key algorithm "public key" that is associated with the component which sent the data is used to decrypt the data component sends data to, and to decrypt the message requires the private key associated with the receiving component. Since the system, which uses an encryption algorithm with a public key, still requires the use of private (or secret) keys, a key management algorithm is required to maintain the private keys that are used in components sold by the vendor, and for tracking these keys.

In some applications, active suspension system can use distributed control algorithm and not the algorithm of centralized management. In this system, the exchange of information between the components of the system can be done in an encrypted form. For example, as shown in Figure 3, system 50 of a vehicle active suspension system includes four actuators 52a-52d, each of which controls a wheel 54a-54d. In contrast to the central controller four local controller 56a-56d receive traffic information from each of the four sensors 58a-58d via the network 60 and manage their respective motor 62a-62d, supporting the car body at the proper level. Each actuator includes an interface 64a-66d of data that includes modules 66a-66d, 68a-68d encryption and decryption, for secure communication between components of the system 50.

Discloses several embodiments. However, it should be understood that within the spirit and scope of the invention various changes may be made. For example, although illustrated in Figures 2-3 two-way secure communication, in some embodiments, can be one-way secure communication (for example, possible to carry out secure communication from the controller to the actuators and unprotected communications - from the actuators to the controllers). Similarly, in some embodiments, can protect only certain types of transmitted information (e.g., encryption only control commands in the absence of other encryption data, such as sensor data). Accordingly, other embodiments are also within the scope of the following claims.