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Drive by wire
Drive by wire or DbW in the automotive industry is the technology that uses electronics or electro-mechanical systems in place of mechanical linkages to control driving functions. The concept is similar to fly-by-wire in the aviation industry. Drive-by-wire may refer to just the propulsion of the vehicle through electronic throttle control, or it may refer to electronic control over propulsion as well as steering and braking, which separately are known as steer by wire and brake by wire, along with electronic control over other vehicle driving functions.
Driver input is traditionally transferred to the motor, wheels, and brakes through a mechanical linkage attached to controls such as a steering wheel, throttle pedal, hydraulic brake pedal, brake pull handle, and so on, which apply mechanical forces. In drive-by-wire systems, driver input does not directly adjust a mechanical linkage, instead the input is processed by an electronic control unit which controls the vehicle using electromechanical actuators. The human–machine interface, such as a steering wheel, yoke, accelerator pedal, brake pedal, and so on, may include haptic feedback that simulates the resistance of hydraulic and mechanical pedals and steering, including steering kickback. Components such as the steering column, intermediate shafts, pumps, hoses, belts, coolers, vacuum servos and master cylinders are eliminated from the vehicle. Safety standards for drive-by-wire are specified by the ISO 26262 standard level D.
Dispensing with mechanical linkages has several advantages: it reduces complexity and simplifies assembly; simplifies service and tuning; reduces the force required to engage inputs and allows it to be customized with haptic technology; allows for more interior design freedom in the placement of input mechanisms; allows for automation of driving functions; reduces cabin noise by eliminating the acoustic linkage to the drive systems; and by reducing floor openings it improves the crash behavior of the vehicle. Because driver inputs can be overridden, safety can be improved by providing computer controlled intervention of vehicle controls with systems such as electronic stability control (ESC), adaptive cruise control and lane assist systems.
Each drive-by-wire system leads to more actuators in the vehicle and therefore greater energy consumption. For instance, the drive-by-wire technology adds actuator motors to create the torque needed to turn the wheels, and a feedback transducer to create the "road feel" on the steering wheel.
Safety considerations require redundancy of driver input sensors, vehicle communication networks, actuators, and other systems. Automotive safety standards such as ISO 26262 require drive-by-wire fail-operational and fail-safe behaviors.
Failures in drive by wire systems can lead to potential hazardous situations where safety depends entirely on the vehicle's failure mode. The Aachen University Institute for Motor Vehicles (ika – Institut für Kraftfahrzeuge Aachen), in collaboration with Mercedes-AMG and others, studies the operation, risks, and safety mechanisms of drive-by-wire systems through its drive-by-wire concept vehicle, SpeedE. Studied scenarios include loss of control over acceleration, brakes, or steering.
Early by-wire systems had mechanical backup systems in case the by-wire systems failed. The modern drive by wire paradigm dispenses with mechanical backups, and relies on redundancy, fail-operational systems, and other safety and security measures: computational redundancy through lockstep CPUs; functional redundancy through modular design where the failure of one module is compensated by an identical module, for example by torque vectoring to compensate for a failed steering or braking module; multi-sensor fault detection; self-isolation of damaged systems; and fault-tolerant communication. Such fail-safes are specified by the ISO 26262 standard level D.
Assessment and standardization of drive-by-wire computer security has also taken place. Researchers demonstrated in 2011 and 2013 that some systems in commercially available vehicles are susceptible to hacking, allowing for external control of the vehicle. Hacking demonstrations included remote activation of systems like the horn, windshield wipers, accelerator, brakes, and transmission. Modern standards such as the ISO/SAE 21434 standard and UNCE regulations 155, 156, and 157 require dedicated cryptographic modules that encrypt all communication between the ECUs and the drive system components.
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Drive by wire AI simulator
(@Drive by wire_simulator)
Drive by wire
Drive by wire or DbW in the automotive industry is the technology that uses electronics or electro-mechanical systems in place of mechanical linkages to control driving functions. The concept is similar to fly-by-wire in the aviation industry. Drive-by-wire may refer to just the propulsion of the vehicle through electronic throttle control, or it may refer to electronic control over propulsion as well as steering and braking, which separately are known as steer by wire and brake by wire, along with electronic control over other vehicle driving functions.
Driver input is traditionally transferred to the motor, wheels, and brakes through a mechanical linkage attached to controls such as a steering wheel, throttle pedal, hydraulic brake pedal, brake pull handle, and so on, which apply mechanical forces. In drive-by-wire systems, driver input does not directly adjust a mechanical linkage, instead the input is processed by an electronic control unit which controls the vehicle using electromechanical actuators. The human–machine interface, such as a steering wheel, yoke, accelerator pedal, brake pedal, and so on, may include haptic feedback that simulates the resistance of hydraulic and mechanical pedals and steering, including steering kickback. Components such as the steering column, intermediate shafts, pumps, hoses, belts, coolers, vacuum servos and master cylinders are eliminated from the vehicle. Safety standards for drive-by-wire are specified by the ISO 26262 standard level D.
Dispensing with mechanical linkages has several advantages: it reduces complexity and simplifies assembly; simplifies service and tuning; reduces the force required to engage inputs and allows it to be customized with haptic technology; allows for more interior design freedom in the placement of input mechanisms; allows for automation of driving functions; reduces cabin noise by eliminating the acoustic linkage to the drive systems; and by reducing floor openings it improves the crash behavior of the vehicle. Because driver inputs can be overridden, safety can be improved by providing computer controlled intervention of vehicle controls with systems such as electronic stability control (ESC), adaptive cruise control and lane assist systems.
Each drive-by-wire system leads to more actuators in the vehicle and therefore greater energy consumption. For instance, the drive-by-wire technology adds actuator motors to create the torque needed to turn the wheels, and a feedback transducer to create the "road feel" on the steering wheel.
Safety considerations require redundancy of driver input sensors, vehicle communication networks, actuators, and other systems. Automotive safety standards such as ISO 26262 require drive-by-wire fail-operational and fail-safe behaviors.
Failures in drive by wire systems can lead to potential hazardous situations where safety depends entirely on the vehicle's failure mode. The Aachen University Institute for Motor Vehicles (ika – Institut für Kraftfahrzeuge Aachen), in collaboration with Mercedes-AMG and others, studies the operation, risks, and safety mechanisms of drive-by-wire systems through its drive-by-wire concept vehicle, SpeedE. Studied scenarios include loss of control over acceleration, brakes, or steering.
Early by-wire systems had mechanical backup systems in case the by-wire systems failed. The modern drive by wire paradigm dispenses with mechanical backups, and relies on redundancy, fail-operational systems, and other safety and security measures: computational redundancy through lockstep CPUs; functional redundancy through modular design where the failure of one module is compensated by an identical module, for example by torque vectoring to compensate for a failed steering or braking module; multi-sensor fault detection; self-isolation of damaged systems; and fault-tolerant communication. Such fail-safes are specified by the ISO 26262 standard level D.
Assessment and standardization of drive-by-wire computer security has also taken place. Researchers demonstrated in 2011 and 2013 that some systems in commercially available vehicles are susceptible to hacking, allowing for external control of the vehicle. Hacking demonstrations included remote activation of systems like the horn, windshield wipers, accelerator, brakes, and transmission. Modern standards such as the ISO/SAE 21434 standard and UNCE regulations 155, 156, and 157 require dedicated cryptographic modules that encrypt all communication between the ECUs and the drive system components.