摘要:
A method and apparatus is provided for validating a plurality of variable data transmitted in an automobile, comprising generating a control copy and a redundant copy of the variable data, calculating a pre-transmittal cross-check measure using the redundant copy of the variable data, and generating a transmittal message using the control copy of the data and the pre-transmittal cross-check measure.
摘要:
Methods and apparatus are provided for determining the duration a motor vehicle engine may operate while operator authorization is verified in response to an ignition request. In one embodiment the method includes the steps of decrementing a pre-authorization timer from a first predetermined time limit and a maximum authorization timer from a second predetermined time limit in response to the ignition request. Also upon receipt of the ignition request an authorization process is initiated. Decrementing of the pre-authorization timer is halted in response to active operation of the starter motor of the motor vehicle, and operation of the motor vehicle is inhibited if either the pre-authorization timer or the maximum authorization timer decrements to zero before completion of the authorization operation.
摘要:
A system and method for implementing cross-network synchronization of nodes on a vehicle bus includes periodically sampling a notion of time from a first network, transmitting a message from the first network to a node on a second network, wherein the message includes the notion of time, and updating a local clock on the second network node based on the notion of time in the message.
摘要:
A vehicle control module for controlling an actuator unit in response to an input having a first processor, a first communication link coupled to the first processor, and a second processor coupled to the first processor via the first communication link. The first processor is configured to generate a first value based on the input, transmit the first value to the actuator unit, and receive a second value from the actuator unit based on a data received by the actuator unit from the first processor. The first communication link is configured to transfer the input and the second value to the second processor. The second processor is configured to determine a third value based on the input, and verify the first value based on a comparison of the second value with the third value.
摘要:
A system and method for implementing cross-network synchronization of nodes on a vehicle bus includes periodically sampling a notion of time from a first network, transmitting a message from the first network to a node on a second network, wherein the message includes the notion of time, and updating a local clock on the second network node based on the notion of time in the message.
摘要:
A method is provided for formatting a message, with a first plurality of bits forming a data component, and a second plurality of bits forming a reserved component, for transmission in a vehicle. The method comprises the steps of calculating an initial checksum from the data component, calculating a revised checksum at least from the initial checksum, and storing the revised checksum in the reserved component. The number of bits in the reserved component is less than the number of bits in the data component.
摘要:
An ignition switch sensor having a plurality of contacts arranged on a sensor to make intermittent contact with a movable contact and generate a first plurality of outputs corresponding to the position of the movable contact relative to the plurality of contacts. A power mode module receives the first plurality of outputs and compares the outputs to data stored within the memory of the module and provides a second plurality outputs according to the value of the first plurality of outputs. A theft resistor may be integrated into the ignition switch sensor circuitry to facilitate protection from tampering and unauthorized starting of the vehicle's engine.
摘要:
Methods and apparatus are provided for insuring that a motor vehicle is being operated by an authorized operator. The apparatus includes an electronic control unit (ECU), an engine immobilizer unit, and a shared encryption key. The ECU generates a challenge by combining the output of a pseudo-random number generator and the output of a somewhat random number generator and cycling the combined number through a linear feedback shift register. The ECU sends the challenge to the immobilizer unit where it is encrypted with the shared key and sent back to the ECU as a response. The ECU uses the same key to encrypt the challenge and compares the encrypted challenge to the response. If the response matches the encrypted challenge, engine operation is enabled.
摘要:
A message filtering system for a communications system in a vehicle enabling communication between various systems and subsystems via a vehicle bus. Electronic devices may be coupled to the bus. Electronic control units (ECUs) may be located therebetween. The ECU may regulate or control the flow of messages between the bus and the electronic devices. Message filters may apply a filter policy to incoming and outgoing messages. In addition, the message filtering system may have an alert policy for violations of the filter policy. In one embodiment, the source identity of outgoing messages may be overwritten by a message filter dedicated to outgoing messages; this message filter may be an application specific integrated circuit.
摘要:
A message filtering system for a communications system in a vehicle enabling communication between various systems and subsystems via a vehicle bus. Electronic devices may be coupled to the bus. Electronic control units (ECUs) may be located therebetween. The ECU may regulate or control the flow of messages between the bus and the electronic devices. Message filters may apply a filter policy to incoming and outgoing messages. In addition, the message filtering system may have an alert policy for violations of the filter policy. In one embodiment, the source identity of outgoing messages may be overwritten by a message filter dedicated to outgoing messages; this message filter may be an application specific integrated circuit.