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In the automotive industry, drive by wire or DbW 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.^[2] Drive-by-wire may refer to just the propulsion of the vehicle through electronic throttle control,^[3] 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.^[4]

Driver input is traditionally transferred mechanically to the drivetrain through a steering wheel and steering column, throttle, hydraulic brakes, brake pull handles and so on. In drive-by-wire systems, driver input is processed by an electronic control unit or carputer 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.

Properties

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.^[6] 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.^[2]

Each drive-by-wire system leads to more actuator 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,^[6] and other systems. Automotive safety standards such as ISO 26262 require drive-by-wire fail-operational and fail-safe behaviors.^[7]

Safety and security

Up-fitted drive-by-wire systems, such as the Paravan Space Drive, have been available since as early as 2003 for existing production vehicles.^[8] Space Drive II is equipped with a redundant power system and triple-redundant communications and processors.

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.^[1]

Early by-wire systems had mechanical backup systems in case the by-wire systems failed.^[3] 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.^[7]

Assessment and standardization of drive-by-wire computer security has also taken place. Researchers demonstrated in 2011^[9] and 2013^[10]^[11] 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.^[11] 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.^[3]

Systems

Brake by wire

A brake-by-wire system eliminates the need for a mechanical connection that transfers force between the brakes and a driver input apparatus such as a pedal or lever. The three main types of brake-by-wire systems are: electronic parking brakes which have, since the turn of the 21st century, become more common; electro-hydraulic brakes (EHB) which can be implemented alongside legacy hydraulic brakes and as of 2020 have found small-scale usage in the automotive industry; and electro-mechanical brakes (EMB) that use no hydraulic fluid, which as of 2020 have yet to be successfully introduced in production vehicles due to their novel actuation methods.^[14]

Shift by wire

Shift-by-wire employs electrical or electronic connections that replace the mechanical connection between the driver's gearshift mechanism and the transmission. Since becoming commercially available in 1996, shift-by-wire has been commonly used in automated manual transmission, and has later been implemented in semi-automatic transmission and automatic transmission.^[6]

Park by wire may be considered a form of shift-by-wire.^[6] Not to be confused with park-brake by wire which engages a parking brake, park-by-wire engages the parking pawl. A parking pawl in a traditional automatic transmission has a mechanical link to the gear stick and locks the transmission in the park position when the gear-shift handle is set in "park". A park-by-wire system uses electronic commands sent to an actuator that engages the parking pawl.

Steer by wire

A vehicle equipped with a steer-by-wire system is able to steer some or all of its wheels without a steering column connected to the wheel axles. It is different from electric power steering or power-assist, as those systems still rely on the steering column to mechanically transfer some steering torque to the wheels.^[15]

A vehicle with a steer-by-wire system may be manually controlled by a driver through a steering wheel, a yoke, or any other steering apparatus which is connected to one or more electronic control units, which uses the input to control steering actuators that turn the wheels and steer the vehicle. The steering wheel or yoke may be equipped with haptic feedback to simulate road feel and wheel resistance, and change depending on the vehicle speed or customizable settings.^[15]^[16]

Throttle by wire

Accelerate-by-wire or throttle-by-wire,^[17] more commonly known as electronic throttle control, is a system that actuates vehicle propulsion without any mechanical connections, such as cables, from the accelerator pedal to the throttle valve of the engine or other propulsion systems. In electric vehicles, this system controls the electric motors by sensing the accelerator pedal input and sending commands to the power inverter modules.

References

^ ^a ^b SpeedE – Forschungsplattform, ika – Institute for Motor Vehicles of RWTH Aachen University, 2016
^ ^a ^b Austin Weber (March 26, 2010), "Wire Processing: Drive-by-Wire", Assembly Magazine
^ ^a ^b ^c ^d Scheibert, Klaus; Kostarigka, Artemis; Dannebaum, Udo; Ambekar, Abhijit; Cai, Wenlin; Heidt, Laurent (2023). "Challenges with the Introduction of X-By-Wire Technologies to Passenger Vehicles and Light Trucks in regards to Functional Safety, Cybersecurity and Availability". SAE Technical Paper Series. Vol. 1. doi:10.4271/2023-01-0581. S2CID 258033364.
^ Pillai, Arjun V.; Manojkumar, B. (2022). "Overview of drive by wire technologies in automobiles". INTERNATIONAL CONFERENCE ON TRENDS IN CHEMICAL ENGINEERING 2021 (ICoTRiCE2021). AIP Conference Proceedings. Vol. 2452. p. 030001. Bibcode:2022AIPC.2452c0001P. doi:10.1063/5.0113232. S2CID 253697706.
^ Chris Rosamond (January 12, 2024), "World first 'everything-by-wire' vehicle breaks all mechanical links to driver", Auto Express
^ ^a ^b ^c ^d Harald Naunheimer; et al. (2011), "9.1.3 Shift-by-Wire", Automotive Transmissions: Fundamentals, Selection, Design and Application (Second ed.), Springer, doi:10.1007/978-3-642-16214-5, ISBN 978-3-642-16213-8
^ ^a ^b Arunkumar Sampath, "Toward functional safety in drive by wire vehicles" (PDF), Mobility Engineering (December 2020)
^ Lydia Saß (July 26, 2023), "25 Jahre PARAVAN", barrierefrei-magazin.de
^ Checkoway, Stephen. "Comprehensive Experimental Analyses of Automotive Attack Surfaces". YouTube. Archived from the original on May 31, 2017. Retrieved August 23, 2018.
^ Greenberg, Andy. "Hackers Reveal Nasty New Car Attacks—With Me Behind The Wheel (Video)". Forbes. Archived from the original on August 25, 2017. Retrieved August 26, 2017.
^ ^a ^b Greenberg, Andy. "Hackers Remotely Kill a Jeep on the Highway—With Me in It". Wired. Archived from the original on January 19, 2017. Retrieved March 6, 2017.
^ ZF presents MOBILITY by-wire technology at IAA, 2023
^ Georg Kacher (July 10, 2023), "2024 Lotus Eletre review: First international drive", Which Car?
^ Dieter Schramm; et al. (2020), "5 Braking systems", Vehicle Technology: Technical foundations of current and future motor vehicles, De Gruyter Oldenbourg, doi:10.1515/9783110595703, ISBN 9783110595703, S2CID 216374738
^ ^a ^b Chris Perkins (March 17, 2023), "How Toyota Is Making the Case for Steer-By-Wire", Road & Track
^ Jancer, Matt. "Take a Look Inside the First Steer-by-Wire Car". Wired. Archived from the original on March 16, 2014. Retrieved March 6, 2017.
^ John Fuller (April 28, 2009), "How Drive-by-wire Technology Works", HowStuffWorks

External links

Fusion of redundant information in brake-by-wire systems, using a fuzzy Voter

[SpeedEpapers-1] SpeedE – Forschungsplattform, ika – Institute for Motor Vehicles of RWTH Aachen University, 2016

[Assembly2010-2] Austin Weber (March 26, 2010), "Wire Processing: Drive-by-Wire", Assembly Magazine

[Scheibert2023-3] Scheibert, Klaus; Kostarigka, Artemis; Dannebaum, Udo; Ambekar, Abhijit; Cai, Wenlin; Heidt, Laurent (2023). "Challenges with the Introduction of X-By-Wire Technologies to Passenger Vehicles and Light Trucks in regards to Functional Safety, Cybersecurity and Availability". SAE Technical Paper Series. Vol. 1. doi:10.4271/2023-01-0581. S2CID 258033364.

[4] Pillai, Arjun V.; Manojkumar, B. (2022). "Overview of drive by wire technologies in automobiles". INTERNATIONAL CONFERENCE ON TRENDS IN CHEMICAL ENGINEERING 2021 (ICoTRiCE2021). AIP Conference Proceedings. Vol. 2452. p. 030001. Bibcode:2022AIPC.2452c0001P. doi:10.1063/5.0113232. S2CID 253697706.

[5] Chris Rosamond (January 12, 2024), "World first 'everything-by-wire' vehicle breaks all mechanical links to driver", Auto Express

[Naunheimer2011-6] Harald Naunheimer; et al. (2011), "9.1.3 Shift-by-Wire", Automotive Transmissions: Fundamentals, Selection, Design and Application (Second ed.), Springer, doi:10.1007/978-3-642-16214-5, ISBN 978-3-642-16213-8

[Sampath2020-7] Arunkumar Sampath, "Toward functional safety in drive by wire vehicles" (PDF), Mobility Engineering (December 2020)

[8] Lydia Saß (July 26, 2023), "25 Jahre PARAVAN", barrierefrei-magazin.de

[9] Checkoway, Stephen. "Comprehensive Experimental Analyses of Automotive Attack Surfaces". YouTube. Archived from the original on May 31, 2017. Retrieved August 23, 2018.

[10] Greenberg, Andy. "Hackers Reveal Nasty New Car Attacks—With Me Behind The Wheel (Video)". Forbes. Archived from the original on August 25, 2017. Retrieved August 26, 2017.

[wired2015-11] Greenberg, Andy. "Hackers Remotely Kill a Jeep on the Highway—With Me in It". Wired. Archived from the original on January 19, 2017. Retrieved March 6, 2017.

[12] ZF presents MOBILITY by-wire technology at IAA, 2023

[Kacher2024Lotus-13] Georg Kacher (July 10, 2023), "2024 Lotus Eletre review: First international drive", Which Car?

[Schramm_2020-14] Dieter Schramm; et al. (2020), "5 Braking systems", Vehicle Technology: Technical foundations of current and future motor vehicles, De Gruyter Oldenbourg, doi:10.1515/9783110595703, ISBN 9783110595703, S2CID 216374738

[RnT-sbw-Toyota-15] Chris Perkins (March 17, 2023), "How Toyota Is Making the Case for Steer-By-Wire", Road & Track

[Q50Wired-16] Jancer, Matt. "Take a Look Inside the First Steer-by-Wire Car". Wired. Archived from the original on March 16, 2014. Retrieved March 6, 2017.

[17] John Fuller (April 28, 2009), "How Drive-by-wire Technology Works", HowStuffWorks

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@@ Line 1: / Line 1: @@
 {{Short description|Automotive technology}}
+{{Use mdy dates|date=July 2023}}
-{{about||the use of electronic control systems in aviation|fly-by-wire}}
 [[File:Erprobungsfahrzeug SpeedE der fka GmbH.jpg|thumb|right|SpeedE, an academic concept car developed for studying drive-by-wire technologies<ref name="SpeedEpapers"/>]]
-'''Drive by wire''' or '''DbW''' technology in the automotive industry is the use of electronic or electro-mechanical systems in place of mechanical linkages that control driving functions. Drive-by-wire may refer to just the [[Ground propulsion|propulsion]] of the vehicle through [[electronic throttle control]],<ref name="Scheibert2023">Scheibert, K., Kostarigka, A., Dannebaum, U., Ambekar, A. et al., "Challenges with the Introduction of X-By-Wire Technologies to Passenger Vehicles and Light Trucks in regards to Functional Safety, Cybersecurity and Availability," SAE Technical Paper 2023-01-0581, 2023, {{doi-inline |10.4271/2023-01-0581|doi: 10.4271/2023-01-0581}}.</ref> 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.<ref>{{citation |doi=10.1063/5.0113232 |url=https://pubs.aip.org/aip/acp/article-abstract/2452/1/030001/2824443/Overview-of-drive-by-wire-technologies-in |title=Overview of drive by wire technologies in automobiles |author=Arjun V. Pillai |date=November 18, 2022 |at=International conference on smart grid & electric vehicle (ICSGEV 2021) 15–16 July 2021 Tamil Nadu, India |journal=AIP Conference Proceedings |volume=2452 |issue=1}}</ref>
+In the [[automotive industry]], '''drive by wire''' or '''DbW''' is the [[technology]] that uses [[electronics]] or [[electro-mechanical]] systems in place of [[mechanical linkage]]s to control driving functions. The concept is similar to [[fly-by-wire]] in the aviation industry.<ref name="Assembly2010" /> Drive-by-wire may refer to just the [[ground propulsion|propulsion]] of the vehicle through [[electronic throttle control]],<ref name="Scheibert2023">{{cite book | doi=10.4271/2023-01-0581 | chapter=Challenges with the Introduction of X-By-Wire Technologies to Passenger Vehicles and Light Trucks in regards to Functional Safety, Cybersecurity and Availability | title=SAE Technical Paper Series | date=2023 | last1=Scheibert | first1=Klaus | last2=Kostarigka | first2=Artemis | last3=Dannebaum | first3=Udo | last4=Ambekar | first4=Abhijit | last5=Cai | first5=Wenlin | last6=Heidt | first6=Laurent | volume=1 | s2cid=258033364 }}</ref> 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.<ref>{{cite book |doi=10.1063/5.0113232 |chapter-url=https://pubs.aip.org/aip/acp/article-abstract/2452/1/030001/2824443/Overview-of-drive-by-wire-technologies-in |volume=2452 |issue=1|bibcode=2022AIPC.2452c0001P |s2cid=253697706 |chapter=Overview of drive by wire technologies in automobiles |title=INTERNATIONAL CONFERENCE ON TRENDS IN CHEMICAL ENGINEERING 2021 (ICoTRiCE2021) |date=2022 |last1=Pillai |first1=Arjun V. |last2=Manojkumar |first2=B. |series=AIP Conference Proceedings |page=030001 }}</ref>
-Driver input is traditionally transferred mechanically to the motor and wheels through a [[steering wheel]] and [[steering column]], [[Car controls#Throttle control|throttle]], [[hydraulic brakes]], [[Parking brake#Pedal or pull handle|brake pull handles]] and so on. In drive-by-wire systems, driver input is processed by an electronic control system 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 technology|haptic feedback]] that simulates the resistance of hydraulic and mechanical pedals and steering. Components such as the steering column, intermediate shafts, pumps, hoses, belts, coolers, [[vacuum servo]]s and master cylinders are eliminated from the vehicle. Similarly, [[fly-by-wire]] systems are widely used in the aviation industry. Safety standards for drive-by-wire are specified by the [[ISO 26262]] standard [[Automotive Safety Integrity Level|level D]].
+Driver input is traditionally transferred mechanically to the [[drivetrain]] through a [[steering wheel]] and [[steering column]], [[car controls#Throttle control|throttle]], [[hydraulic brakes]], [[parking brake#Pedal or pull handle|brake pull handles]] and so on. In drive-by-wire systems, driver input is processed by an [[electronic control unit]] or [[carputer]] 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 technology|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 servo]]s and master cylinders are eliminated from the vehicle. Safety standards for drive-by-wire are specified by the [[ISO 26262]] standard [[Automotive Safety Integrity Level|level D]].
 == Properties ==
+[[File:REE Automotive P7-C class 4 electric truck with Knapheide vocational body Work Truck Week 2024 facing left.jpg|thumb|right|alt=REE Automotive P7-C class 4 electric truck.|The [[REE Automotive|REE]] P7-C truck is the first commercially available vehicle to be road-certified in the United States with all by-wire controls, including drive, steer, brake,<ref>{{citation |url=https://www.autoexpress.co.uk/news/362018/world-first-everything-wire-vehicle-breaks-all-mechanical-links-driver |title=World first 'everything-by-wire' vehicle breaks all mechanical links to driver |author=Chris Rosamond |date=January 12, 2024 |website=[[Auto Express]]}}</ref> and park-brake by-wire, collectively called x-by-wire.<ref name="Scheibert2023" />]]
-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 [[Automotive design#Interior design|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 [[Automotive safety|crash behavior]] of the vehicle.<ref name="Naunheimer2011"/><ref name="Naunheimer2011">{{citation |title=Automotive Transmissions: Fundamentals, Selection, Design and Application |edition=Second |publisher=Springer |author=Harald Naunheimer |isbn=978-3-642-16213-8 |doi=10.1007/978-3-642-16214-5 |year=2011 |display-authors=etal |chapter=9.1.3 Shift-by-Wire}}</ref>
+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 [[Automotive design#Interior design|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 [[Automotive safety|crash behavior]] of the vehicle.<ref name="Naunheimer2011">{{citation |title=Automotive Transmissions: Fundamentals, Selection, Design and Application |edition=Second |publisher=Springer |author=Harald Naunheimer |isbn=978-3-642-16213-8 |doi=10.1007/978-3-642-16214-5 |year=2011 |display-authors=etal |chapter=9.1.3 Shift-by-Wire}}</ref> 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), [[Autonomous cruise control system|adaptive cruise control]] and [[Lane departure warning system|lane assist systems]].<ref name="Assembly2010">{{citation |url=https://www.assemblymag.com/articles/87508-wire-processing-drive-by-wire |title=Wire Processing: Drive-by-Wire |author=Austin Weber |date=March 26, 2010 |website=Assembly Magazine}}</ref>
+Each drive-by-wire system leads to more actuator 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.
-Because driver inputs can be bypassed, safety can be improved by providing computer controlled intervention of vehicle controls with systems such as [[electronic stability control]] (ESC), [[Autonomous cruise control system|adaptive cruise control]] and [[Lane departure warning system|Lane Assist Systems]]. Some systems, with appropriate modification, allow for control by laptops or even game controllers.<ref>{{cite web|url=https://www.techradar.com/uk/news/i-used-a-ps4-controller-to-drive-a-real-car-remotely-and-it-was-awesome|title=I used a PS4 controller to drive a car|date=12 October 2017|publisher=TechRadar|access-date=2018-08-03|archive-date=2018-08-03|archive-url=https://web.archive.org/web/20180803163701/https://www.techradar.com/uk/news/i-used-a-ps4-controller-to-drive-a-real-car-remotely-and-it-was-awesome|url-status=live}}</ref>
+Safety considerations require [[Redundancy (engineering)|redundancy]] of driver input sensors, [[CAN bus|vehicle communication network]]s, actuators,<ref name="Naunheimer2011" /> and other systems. Automotive safety standards such as [[ISO 26262]] require drive-by-wire [[Safety-critical system#Reliability regimes|fail-operational and fail-safe]] behaviors.<ref name="Sampath2020" />
-[[Ergonomic]]s can be improved by the amount of force and range of movement required by the driver and by greater flexibility in the location of controls.  This flexibility also significantly expands the number of options for the vehicle's design.
-Each drive-by-wire system leads to more motors in the vehicle and therefore a 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 and security ==
+[[File:Space Drive Paravan.webm|thumb|Up-fitted drive-by-wire systems, such as the [[:de:Paravan|Paravan]] Space Drive, have been available since as early as 2003 for existing production {{nowrap|vehicles.<ref>{{citation |url=https://barrierefrei-magazin.de/artikel/25-jahre-paravan/ |title=25 Jahre PARAVAN |author=Lydia Saß |date=July 26, 2023 |website=barrierefrei-magazin.de}}</ref>}} Space Drive II is equipped with a redundant power system and {{nowrap|triple-[[Redundancy (engineering)|redundant]]}} communications and processors.]]
-Research about the safety of drive-by-wire systems has been ongoing since 2011 at the [[Aachen University]] Institute for Motor Vehicles (ika - Institut für Kraftfahrzeuge) in collaboration with [[Mercedes-AMG]] and others. Failures in drive by wire systems can lead to potential hazardous situations where safety depends entirely on the vehicle's [[Safety-critical system#Reliability regimes|failure mode]]. Several papers published by the institute detail the operation, risks, and safety mechanisms of its concept vehicle's drive-by-wire systems. Scenarios include loss of control over acceleration, brakes, or steering. The institute's concept vehicle, SpeedE, was designed to avoid [[Redundancy (engineering)|safety through redundancy]] in many of its systems, though a redundant mechanical braking system was implemented.<ref name="SpeedEpapers">{{citation |url=https://www.ika.rwth-aachen.de/de/kompetenzen/projekte/fahrzeugkonzepte-und-design/speede-de.html |title=SpeedE - Forschungsplattform |year=2016 |publisher=ika - Institute for Motor Vehicles of RWTH Aachen University}}</ref> Contrarily, the modern drive by wire paradigm replaces mechanical fail-safes with redundancy fail-safes and other security measures: computational redundancy through [[Lockstep (computing)|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 [[Automotive Safety Integrity Level|level D]].<ref name="Sampath2020">{{citation |url=https://saeindia.org/jbframework/uploads/2020/12/Tech-Trends-Towards-Functional-Safety-in-Drive-By-Wire-Vehicles-compressed.pdf |title=Toward functional safety in drive by wire vehicles |author=Arunkumar Sampath |journal=Mobility Engineering |issue=December 2020}}</ref>
+Failures in drive by wire systems can lead to potential hazardous situations where safety depends entirely on the vehicle's [[Safety-critical system#Reliability regimes|failure mode]]. The [[Aachen University]] Institute for Motor Vehicles (ika – [[:de:Institut für Kraftfahrzeuge Aachen|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.<ref name="SpeedEpapers">{{citation |url=https://www.ika.rwth-aachen.de/de/kompetenzen/projekte/fahrzeugkonzepte-und-design/speede-de.html |title=SpeedE – Forschungsplattform |year=2016 |publisher=ika – Institute for Motor Vehicles of RWTH Aachen University}}</ref>
+Early by-wire systems had mechanical backup systems in case the by-wire systems failed.<ref name="Scheibert2023" /> The modern drive by wire paradigm dispenses with mechanical backups, and relies on [[Redundancy (engineering)|redundancy]], [[Safety-critical system#Reliability regimes|fail-operational]] systems, and other safety and security measures: computational redundancy through [[Lockstep (computing)|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 [[Automotive Safety Integrity Level|level D]].<ref name="Sampath2020">{{citation |url=https://saeindia.org/jbframework/uploads/2020/12/Tech-Trends-Towards-Functional-Safety-in-Drive-By-Wire-Vehicles-compressed.pdf |title=Toward functional safety in drive by wire vehicles |author=Arunkumar Sampath |journal=Mobility Engineering |issue=December 2020}}</ref>
-Assessment and standardization of drive-by-wire [[computer security]] has also taken place. Researchers demonstrated in 2011<ref>{{cite web |last1=Checkoway |first1=Stephen |title=Comprehensive Experimental Analyses of Automotive Attack Surfaces |url=https://www.youtube.com/watch?v=bHfOziIwXic |website=YouTube |access-date=23 August 2018 |archive-date=31 May 2017 |archive-url=https://web.archive.org/web/20170531064515/https://www.youtube.com/watch?v=bHfOziIwXic |url-status=live }}</ref> and 2013<ref>{{cite web|url=https://www.forbes.com/sites/andygreenberg/2013/07/24/hackers-reveal-nasty-new-car-attacks-with-me-behind-the-wheel-video/|title=Hackers Reveal Nasty New Car Attacks--With Me Behind The Wheel (Video)|first=Andy|last=Greenberg|access-date=2017-08-26|archive-date=2017-08-25|archive-url=https://web.archive.org/web/20170825000835/https://www.forbes.com/sites/andygreenberg/2013/07/24/hackers-reveal-nasty-new-car-attacks-with-me-behind-the-wheel-video/|url-status=live}}</ref><ref name="wired2015">{{cite web|url=https://www.wired.com/2015/07/hackers-remotely-kill-jeep-highway/|title=Hackers Remotely Kill a Jeep on the Highway—With Me in It|first=Andy|last=Greenberg|access-date=2017-03-06|archive-date=2017-01-19|archive-url=https://web.archive.org/web/20170119103855/https://www.wired.com/2015/07/hackers-remotely-kill-jeep-highway/|url-status=live}}</ref> that some systems in commercially-available vehicles are susceptible to [[Security hacker|hacking]], allowing for external control of the vehicle. Hacking demonstrations included remote activation of systems like the horn, windshield wipers, accelerator, brakes, and transmission.<ref name="wired2015" /> Modern standards such as the [[IT security standards#ISO/SAE 21434|ISO/SAE 21434]] standard and [[Regulation of self-driving cars#UNECE WP.29 GRVA|UNCE regulations 155, 156, and 157]] require dedicated [[cryptographic module]]s that encrypt all communication between the ECUs and the drive system components.<ref name="Scheibert2023" />
+Assessment and standardization of drive-by-wire [[computer security]] has also taken place. Researchers demonstrated in 2011<ref>{{cite web |last1=Checkoway |first1=Stephen |title=Comprehensive Experimental Analyses of Automotive Attack Surfaces |url=https://www.youtube.com/watch?v=bHfOziIwXic |website=YouTube |access-date=August 23, 2018 |archive-date=May 31, 2017 |archive-url=https://web.archive.org/web/20170531064515/https://www.youtube.com/watch?v=bHfOziIwXic |url-status=live }}</ref> and 2013<ref>{{cite web|url=https://www.forbes.com/sites/andygreenberg/2013/07/24/hackers-reveal-nasty-new-car-attacks-with-me-behind-the-wheel-video/|title=Hackers Reveal Nasty New Car Attacks—With Me Behind The Wheel (Video)|first=Andy|last=Greenberg|website=[[Forbes]] |access-date=2017-08-26|archive-date=2017-08-25|archive-url=https://web.archive.org/web/20170825000835/https://www.forbes.com/sites/andygreenberg/2013/07/24/hackers-reveal-nasty-new-car-attacks-with-me-behind-the-wheel-video/|url-status=live}}</ref><ref name="wired2015">{{cite magazine|url=https://www.wired.com/2015/07/hackers-remotely-kill-jeep-highway/|title=Hackers Remotely Kill a Jeep on the Highway—With Me in It|first=Andy|last=Greenberg|magazine=Wired |access-date=2017-03-06|archive-date=2017-01-19|archive-url=https://web.archive.org/web/20170119103855/https://www.wired.com/2015/07/hackers-remotely-kill-jeep-highway/|url-status=live}}</ref> that some systems in commercially-available vehicles are susceptible to [[Security hacker|hacking]], allowing for external control of the vehicle. Hacking demonstrations included remote activation of systems like the horn, windshield wipers, accelerator, brakes, and transmission.<ref name="wired2015" /> Modern standards such as the [[IT security standards#ISO/SAE 21434|ISO/SAE 21434]] standard and [[Regulation of self-driving cars#UNECE WP.29 GRVA|UNCE regulations 155, 156, and 157]] require dedicated [[cryptographic module]]s that encrypt all communication between the ECUs and the drive system components.<ref name="Scheibert2023" />
 == Systems ==
+[[File:Lotus Eletre 010 (cropped).jpg|thumb|right|alt=Lotus Eletre|A model of the [[Lotus Eletre]] with drive-, steer-, and brake-by-wire provided by [[ZF Friedrichshafen|ZF Group]]<ref>{{citation |url=https://www.iaa-mobility.com/en/newsroom/news/cars/zf-drive-by-wire |title=ZF presents MOBILITY by-wire technology at IAA |year=2023}}</ref> is planned for 2025<ref name="Kacher2024Lotus">{{citation |url=https://www.whichcar.com.au/reviews/2024-lotus-eletre-review-iirst-international-drive |title=2024 Lotus Eletre review: First international drive |date=July 10, 2023 |author=Georg Kacher |website=Which Car?}}</ref>]]
-[[File:Electric vehicle corner module simplified diagram.png|thumb|right|alt=Simplified diagram of a corner module for an electric vehicle.|[[REE Automotive#Corner modules|REE Automotive electric vehicle corner module]] diagram. The module implements drive, steer, brake, and park by-wire, collectively called x-by-wire.<ref name="Scheibert2023"/>]]
 === Brake by wire ===
 {{Main|Brake-by-wire}}
+A brake-by-wire system eliminates the need for a mechanical connection that transfers force between the brakes and a driver input apparatus such as a [[brake pedal|pedal]] or [[parking brake|lever]]. The three main types of brake-by-wire systems are: [[electronic parking brake]]s which have, since the turn of the 21st century, become more common; [[electro-hydraulic brake]]s (EHB) which can be implemented alongside legacy [[hydraulic brakes]] and as of 2020 have found small-scale usage in the automotive industry; and [[electro-mechanical brake]]s (EMB) that use no hydraulic fluid, which as of 2020 have yet to be successfully introduced in production vehicles due to their novel actuation methods.<ref name="Schramm 2020">{{citation |title=Vehicle Technology: Technical foundations of current and future motor vehicles |author=Dieter Schramm |display-authors=etal |chapter=5 Braking systems |doi=10.1515/9783110595703 |publisher=De Gruyter Oldenbourg |year=2020|isbn=9783110595703 |s2cid=216374738 }}</ref>
-A pure brake by wire system would eliminate the need for hydraulics completely by using motors to actuate calipers, in comparison to the currently existing technology where the system is designed to provide braking effort by building hydraulic pressure in the brake lines
-=== Park by wire ===
-{{Main|Park by wire}}{{distinguish|Parking brake}}
-The [[parking pawl]] in a traditional automatic transmission has a mechanical link to the gear lever and locks the transmission in the park position when the vehicle is set in Park. A park  by wire system uses electronic commands to actuate the parking pawl by a motor when the driver puts the vehicle in park.
 === Shift by wire ===
 {{Main|Shift by wire}}
+Shift-by-wire employs electrical or electronic connections that replace the [[Linkage (mechanical)|mechanical connection]] between the driver's [[gearshift]] mechanism and the [[Transmission (mechanical device)|transmission]]. Since becoming commercially available in 1996, shift-by-wire has been commonly used in [[automated manual transmission]], and has later been implemented in [[semi-automatic transmission]] and [[automatic transmission]].<ref name="Naunheimer2011" />
-The direction of motion of the vehicle (Forward, Reverse) is set by commanding the actuators inside the transmission through electronic commands based on the current input from the driver (Park, Reverse, Neutral or Drive).
+[[Park by wire]] may be considered a form of shift-by-wire.<ref name="Naunheimer2011" /> Not to be confused with [[#Brake by wire|park-brake by wire]] which engages a [[parking brake]], park-by-wire engages the [[parking pawl]]. A parking pawl in a traditional automatic transmission has a mechanical link to the [[gear stick]] and locks the transmission in the park position when the gear-shift handle is set in "park". A park-by-wire system uses electronic commands sent to an actuator that engages the parking pawl.
 === Steer by wire ===
 {{Main|Steer-by-wire}}
-[[File:Show case of Uniti steer-by-wire system at the 2016 CeBit.jpg|thumb|European Commissioner [[Günther Oettinger]] driving a [[Uniti (automobile)|Uniti]] car simulator with a simulated steer-by-wire system<ref>{{citation |url=https://www.euronews.com/2017/04/08/uniti-sweden-the-diversity-behind-the-electric-car-of-the-future |title= Uniti Sweden: the diversity behind the electric car of the future |website=Euronews |date=April 8, 2017}}</ref> and [[augmented reality]] [[Head-up display|HUD]] at [[CeBIT]] 2016.]]
 A vehicle equipped with a steer-by-wire system is able to steer some or all of its wheels without a [[steering column]] connected to the wheel axles. It is different from [[electric power steering]] or power-assist, as those systems still rely on the steering column to mechanically transfer some steering torque to the wheels.<ref name="RnT-sbw-Toyota">{{citation |url=https://www.roadandtrack.com/news/a43350167/toyota-steer-by-wire/ |title=How Toyota Is Making the Case for Steer-By-Wire |author=Chris Perkins |date=March 17, 2023 |website=Road & Track}}</ref>
-A vehicle with a steer-by-wire system may be manually controlled by a driver through a steering wheel, a yoke, or any other steering apparatus which is connected to one or more [[electronic control unit]]s, which uses the input to control steering actuators that turn the wheels and steer the vehicle. The steering wheel or yoke may be equipped with [[haptic technology|haptic feedback]] to simulate road feel and wheel resistance, and change depending on the vehicle speed or customizable settings.<ref name="RnT-sbw-Toyota" /><ref name="Q50Wired">{{cite web|url=https://www.wired.com/2013/05/al-drivebywire/|title=Take a Look Inside the First Steer-by-Wire Car|first=Matt|last=Jancer|access-date=2017-03-06|archive-date=2014-03-16|archive-url=https://web.archive.org/web/20140316025422/http://www.wired.com/autopia/2013/05/al_drivebywire|url-status=live}}</ref>
+A vehicle with a steer-by-wire system may be manually controlled by a driver through a steering wheel, a yoke, or any other steering apparatus which is connected to one or more [[electronic control unit]]s, which uses the input to control steering actuators that turn the wheels and steer the vehicle. The steering wheel or yoke may be equipped with [[haptic technology|haptic feedback]] to simulate road feel and wheel resistance, and change depending on the vehicle speed or customizable settings.<ref name="RnT-sbw-Toyota" /><ref name="Q50Wired">{{cite magazine|url=https://www.wired.com/2013/05/al-drivebywire/|title=Take a Look Inside the First Steer-by-Wire Car|first=Matt|last=Jancer|magazine=Wired |access-date=2017-03-06|archive-date=2014-03-16|archive-url=https://web.archive.org/web/20140316025422/http://www.wired.com/autopia/2013/05/al_drivebywire|url-status=live}}</ref>
 === Throttle by wire ===
 {{Main|Electronic throttle control}}
-This system helps accomplish vehicle propulsion by means of an electronic throttle without any cables from the accelerator pedal to the throttle valve of the engine. In electric vehicles, this system controls the electric motors by sensing the accelerator pedal input and sending commands to the power inverter modules.
+Accelerate-by-wire or throttle-by-wire,<ref>{{citation|url=https://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/drive-by-wire.htm |title=How Drive-by-wire Technology Works |author=John Fuller |date=April 28, 2009 |website=HowStuffWorks}}</ref> more commonly known as [[electronic throttle control]], is a system that actuates vehicle propulsion without any mechanical connections, such as cables, from the accelerator pedal to the throttle valve of the engine or other [[ground propulsion|propulsion]] systems. In electric vehicles, this system controls the electric motors by sensing the accelerator pedal input and sending commands to the power inverter modules.
 == References ==

v t e Internal combustion engine
Part of the Automobile series
Engine block and rotating assembly	Balance shaft Block heater Bore Connecting rod Crankcase Crankcase ventilation system (PCV valve) Crankpin Crankshaft Core plug (freeze plug) Cylinder (bank, layout) Displacement Flywheel Firing order Stroke Main bearing Piston Piston ring Starter ring gear
Valvetrain and Cylinder head	Flathead layout Overhead camshaft layout Overhead valve (pushrod) layout Tappet / lifter Camshaft Chest Combustion chamber Compression ratio Head gasket Rocker arm Timing belt Valve
Forced induction	Blowoff valve Boost controller Intercooler Supercharger Turbocharger
Fuel system	Diesel engine Petrol engine Carburetor Fuel filter Fuel injection Fuel pump Fuel tank
Ignition	Magneto Compression ignition Coil-on-plug Distributor Glow plug Ignition coil Spark plug Spark plug wires
Engine management	Engine control unit (ECU)
Electrical system	Alternator Battery Dynamo Starter motor
Intake system	Airbox Air filter Idle air control actuator Inlet manifold MAP sensor MAF sensor Throttle Throttle position sensor
Exhaust system	Catalytic converter Diesel particulate filter EGT sensor Exhaust manifold Muffler Oxygen sensor
Cooling system	Air cooling Water cooling Electric fan Radiator Thermostat Viscous fan (fan clutch)
Lubrication	Oil Oil filter Oil pump Sump (Wet sump, Dry sump)
Other	Knocking / pinging Power band Redline Stratified charge Top dead centre
Portal Category

v t e Powertrain
Part of the Automobile series
Automotive engine	Diesel engine Electric Fuel cell Hybrid (Plug-in hybrid) Internal combustion engine Petrol engine Steam engine
Transmission	Automatic transmission Chain drive Direct-drive Clutch Constant-velocity joint Continuously variable transmission Coupling Differential Direct-shift gearbox Drive shaft Dual-clutch transmission Drive wheel Automated manual transmission Electrorheological clutch Epicyclic gearing Fluid coupling Friction drive Gearshift Giubo Hotchkiss drive Limited-slip differential Locking differential Manual transmission Manumatic Parking pawl Park-by-wire Preselector gearbox Semi-automatic transmission Shift-by-wire Torque converter Transaxle Transfer box Transmission control unit Universal joint
Wheels and tires	Wheel hub assembly Wheel Rim Alloy wheel Hubcap Tire Off-road Racing slick Radial Rain Run-flat Snow Spare Tubeless
Hybrid	Electric motor Hybrid vehicle drivetrain Electric generator Alternator
Portal Category

v t e Chassis control system
Part of the Automobile series
Suspension	Anti-roll bar (sway bar) Axle Axle track Beam axle Camber angle Car handling Coil spring De Dion tube Double wishbone Hydrolastic (Hydragas) Hydropneumatic Independent suspension Leaf spring Live axle MacPherson strut Multi-link suspension Panhard rod Shock absorber Swing axle Toe angle Torsion bar Trailing arm Unsprung mass Watt's linkage Wheel alignment Wheelbase
Steering	Ackermann steering geometry Caster angle Kingpin Oversteer Power steering Rack and pinion Torque steering Understeer
Brakes	Automatic braking Anti-lock braking system Active rollover protection Brake bleeding Brake fade Brake fluid Brake lining Combined braking system Disc brake Drum brake Electric park brake Electronic brakeforce distribution Electronic stability control Engine braking Hydraulic brake Hydraulic fluid Inboard brake Parking brake Regenerative brake Vacuum servo
Roadwheels Tires (Tyres)	Alloy wheel Custom wheel Drive wheel Hubcap Outline of tires Rostyle wheel Spinner Whitewall tire Wire wheels
Portal Category