While there are numerous advantages to this system, including increased gas mileage and a less labor intensive fix, there are also certain disadvantages to electric power steering. Only highperformance mcus can provide sufficient computing power and specialized peripherals for complex motor control functions. As epas electric power assisted steering systems have been developed and refined however, manufacturers like porsche have managed to create electronic systems that all but match the feel of a. First, a reference model is employed to generate ideal motor. Excellent power density and good acoustics, paired with high efficiency, low friction, and low harmonics, provide these drives a special note in the safety area of electric power steering systems. Design and fullcar tests of electric power steering system. Electric power steering electric power steering eps systems have attracted much attention for their advantages with respect to improved fuel economy and have been widely adopted as automotive power steering equipment in recent years. Pdf study on electric power steering system based on adams. Replacing the hydraulics in the power steering system is the small electric motor which controls the entire functioning of the power steering system.
A wide variety of universal electric power steering options are available to you, there are 196 suppliers who sells universal electric power steering on, mainly located in asia. Eps system power steering 9 of four types of eps systems. Future steering systems the main feature of future steering systems is the missing direct mechanical link between steering wheel and steered wheels. Auxiliary power supply system for electric power steering.
This thesis also covers various aspects of hydraulic power assisted steering systems in road vehicles. Pdf electric power steering system eps has been used to replace traditional hydraulic power steering system hps in automobiles. Electric power steering kit from car steering wholesale. Center the steering wheel and then turn the power switch on ig. Hydraulic power steering system linkedin slideshare. Most eps systems have variable assist, which provides more assistance as the speed of a vehicle decreases, and less assistance from the system during high. The system offers a speeddependent steering assistance with active return and various driver assistance functions for automated driving. The big steering wheel still graced steering columns until the 1970s, but the systems were growing more sensitive to inputs at high speeds. Hydraulic steering wheel, once very popular, is getting replaced by electronic steering wheel in modern cars. Electrically assisted power steering eps is the latest technological cross we bear. This results in power dissipation through the continuous.
Hydraulic power steering system design in roadanalysis. Electric power steering eps system is an alternative to traditional steering systems, such as hydraulic and electrohydraulic systems. The top countries of supplier is china, from which the percentage of universal electric power steering supply is 100% respectively. Koyo epas, japan little power is used or wasted when the vehicle is running at a reasonable speed or when steering is not required. With an restraints air bag mounted in the centre hub of the wheel to protect the driver in frontal and severe impacts and a series of multifunctional buttons to enable the driver to operate a multitude. Power assisted hydraulic steering systems which are in use are mentioned below. Power steering 8 of ephs replaces customary drive belts and pulleys in a conventional rackandpinion system. Ultimate power steering has found a solution to this issue by fitting an electric power steering pump. Power steering is a system for reducing the steering effort by using an external power source to assist in turning the wheels.
Unit one steering system design 47 a4u1l3 figure 5 speed controlled variable power steering gear the system provides full assist for evasive maneuvers at higher speeds. Electric power steering systems 01 02 2005 2010 2015 2020 2025 2030 safety reliability collision safety reduce accidents. A dynamic model of the steering system is derived in 7, where the authors. The act of guiding or showing the way steering mechanism. Power steering systems date back to 1925 when they were first introduced by the detroit pump manufacturer vickers.
Steering systems steering wheel the steering wheel has become a very sophisticated and multifunctional assembly. Your hydraulic power steering system can drain as much as 58 hp from your engine and cost you somewhere between mpg of fuel. Electric power steering is a power steering system that uses computers, electronic sensors and a small electric engine to replace traditional, hydraulic power steering. Electric power steering eps systems application note 8 v 0. Automotive electric power steering eps market growth. Electric power steering design guide with drv3205q1 1 introduction the automotive market is ever evolving and always looking for more protections and diagnostics with reliable and spacesaving solutions in safetycritical market niches, such as electric power steering eps and electronic braking systems ebs. You can expect to see several innovations that will improve fuel economy. Control of an electric power assisted steering system using. The unit is a zf pump that we have sourced, that we supply as a universal kit so you can mount it remotely away from the engine bay if needed. Most electric power steering systems use a threephase electric motor powered by a pulse width modulated dc voltage.
Power steering gives a feedback of forces acting on the front wheel to give a sense of how wheels are interacting with the road. Power steering is viewed as a dynamic system and is investigated with linear and nonlinear modeling techniques. Brushless motor eas eliminates all hydraulic components and fluid. The article introduces a new eps control system that reduces steering torque during static steering i. Electric power steering systems with the servo unit on a second pinion are designed for midsize or upper midsize cars. Because of the many components of the power steering and steering gear systems, and due to their cohesive nature, an inspection of these systems should be thorough. Today, the direction of development for steering systems is evidently towards electric power steering eps systems. Power steering 7 of valve moves and uncovers return port to pump inlet. This design allows for lower inertia, lower friction and more direct steering feel, as well as superior response. Electric power steering systems eps have never been. System theoretic process analysis of electric power steering for automotive applications by rodrigo sotomayor martinez s. The dynamic characteristics of electric power steering eps systems can be characterized by the transmissibility from rack load to steering wheel torque. Design and fullcar tests of electric power steering system 743 electronic control with the aim of further improving functions and performance. Electric power steering column noise motor vehicle.
Jtekt developed the worlds first electric power steering eps system in 1988. Electric power assisted steering eps uses an electric motor to provide directional control to the driver, without any hydraulic. Steering and suspension systems must constrain the wheel if it is to stay, say, in the plane oa. The disadvantages of electric power steering it still runs. Eps also enables adas features, such as lane keeping, park assist, active return to. The power steering pump drive belt is a simple, but very important, component in the power steering system. The motors for these electric power steering systems are highlyintegrated, automatically producible, permanentlyexcited synchronous machines. Bmw introduced a separate 24 v powersupply system to enable electrical steering systems for all variants of the 5series launched in 20102. The valve design in terms of area gradient is essential for the function of the hpas system. Electric power steering eps system parts solutions nxp. Electric power steering system the market share for eps systems is expected to increase over the next decade. By adapting a hydraulic power steering, you can smoothly and comfortably maneuver the vehicle, regardless of its size or weight.
Power steering electronic power steering system ps7 ps 2 when reconnecting a connector related to the electric power steering system, ensure that the power switch is off. When the steering wheel is turned to the right, for example, fluid passages v 1 and v 3 are opened while fluid passages v 2 and v 4 are nearly closed. Electronic power steering systems eliminate the need for a pump, hoses and a drive belt connected to the engine using variable amounts of power. What is powering the steering system in your vehicle.
A power steering pump in perfect condition will not produce the required pressure for steering assist if the drive belt is slipping. The power steering system typically includes a pump, power steering fluid, a pressure hose. Pdf design of the auto electric power steering system. Especially motor vehicle functions of steering systems it helps in swinging the wheels to the left. Electric power steering gives better response at different speeds as compared to hydraulic power steering. Control of an electric power assisted steering system. Analyzing electrical actuators currently in existence, it can be found that for small and middle size vehicles, the. Eps eliminates many hps components such as the pump, hoses, fluid, drive belt, and pulley.
Electric power steering design guide with drv3205q1. Column drive electric power steering currently there are four different types of electric power steering system, all based on rack and pinion steering. The power steering belt should be inspected for damage, cracking, wear, and tightness. This pressure, in turn, assists the steering mechanism in directing the tires as you turn the steering wheel. More on tire cornering forces the slip angle, is shown here as the angle between the. With the help of the drivers steering input, the speed, dynamics and other suspension related controls can be monitored and controlled with electric power steering kit. Three phase motors allow for faster and more precise application of torque at low rpms. Eps also offers greater handling and steering feel while improving vehicle safety by adopting the steering torque to the vehicles speed and providing active torque in critical driving situations. The pressure to introduce eps systems for all segments is high enough to make e.
Electricpower steering electricpower steering eps systems have attracted much attention for their advantages with respect to improved fuel economy and have been widely adopted as automotive powersteering equipment in recent years. Study on electric power steering system based on adams article pdf available in procedia engineering 15. There are many brands of power steering fluid designed for use in all steering systems. Features that are being proposed include the introduction of intelligent control strategy and the application of power steering, which. The wheeled vehicle steering systems subcourse, part of the light wheel vehicle mechanic mos 63b skill level 3 course, is designed to teach the knowledge necessary to develop the skills for servicing and maintaining steering systems. Eclectic power steering is less prone to problems and faults and are more durable as compared to hydraulic power steering. Electric power steering automotive products nsk global. Hydraulic steering wheel has a hydraulic piston connected to the steering gear, and steering gears internal cavity is divided into two chambers. Its almost thirty years since the first series production electric power steering eps appeared in the 1988 suzuki cervo. Even if the power fails, driver can steer only it becomes more heavier. Various types of steering systems, drive belts, and pump designs are described in this lecture. Within ten years, power steering was an option or standard on all americanbuilt vehicles.
I have a 2014 honda accord coupe equipped with electric power steering eps. They have many advantages over traditional hydraulic power steering systems in engine independence fuel economy energy, tunability of steering feel, modularityqui ck assembly, compact size and environmental compatibility, 1. Do not turn the power switch on ig when the steering wheel is not centered. This epsp can be mounted away from the engine and is a simple stand alone electric pump. May 20, 2016 although any kind of power steering fluid will usually work, performance is often optimized by using the manufacturers label, which can be bought from any parts supplier for that make of car. The first version of electric power assisted steering epas was the changing of the power source for the traditional hydraulic power steering from a mechanical pump, driven off the engine via a belt drive arrangement to an electrically driven pump.
The motor is brushless and has an operating voltage range of 9 to 16 volts. Electric power assisted steering system for automobiles. System, brushed dc motor, permanent magnet ac synchronous motor, power. Also hybrid hydraulicelectric systems were developed.
The prototype is bent by hand, drilled and welded just the frame, not the car. Electric power assisted steering electro hydraulic power steering ep as systems the first version of electric power assisted steering was the changing of the power s ource for the traditional hydraulic power steering from a mechanical pump, driven off the engine via a belt drive arrangement to an electr ically driven pump. The configuration of an eps system can allow the entire power assist system to be packaged on the rack and pinion steering gear or in the steering column. The stiffness of power assisted rackandpinion steering gear has been analyzed in 6. Torque sensor, torsion bar, position sensor, electric power steering. Pudlo abstract this paper presents a new control strategy of electric power assisted steering epas systems to ensure several control objectives. Committed to producing superior steering equipment. Conventional power steering systems us e an engine accessor y b elt t o. Iii electric power assisted steering system for automobiles m. Traditional power steering systems are hydraulic systems, but electric power steering eps is becoming much more common. Our components have been tested to ensure they work seamlessly and fulfill the highestpossible safety standards. The sensors send information about the steering torque, driving speed, and the steering angle.
This chapter gives a detailed overview of the mechanical and electrical system components and their principle concept based on a column epas system from the global steering system supplier nsk. Electro hydraulic power steering ep as systems electric. Design comparison of two rotating electrical machines for 42v. The transmissibility can be studied by fixing the steering wheel and calculating the frequency response from the rack load to the torque needed t. The principal eps systems proposed by industry for small and middle size vehicles are mounted on the pinion steering gear, eliminating parasitic losses normally associated with hydraulic power steering systems. The automotive electric power steering eps market was valued at usd 19. When cranking the steering wheel, i can hear a noise coming from the steering column, mostly at slow speed like backing out of a parking spot.
A torque sensor connected to the steering shaft controls a computer that then tells this mechanism when to engage and provide steering assistance. Pdf electric power steering eps is a full electric system, which reduces the amount of steering effort by directly applying the output from an. Power steering systems supplement the torque that the driver applies to the steering wheel. Diagnosing electric power steering systems requires an understanding of voltage, current and loads. Epas systems are more energy efficient than hydraulic steering system but are limited to small and mediumsized automobiles. E lectric power assisted steering systems epas are replacing hydraulic power steering in many new vehicles today. Also, electronic power steering systems are smaller and lighter than hydraulic systems. Control of an electronic power steering system for people with. Eps electric power steering new vishay intertechnology. Conventional power steering systems us e an engine accessor y. Power steering utilizes a hydraulic pump running off a beltdriven by the engine, this pump enables a small amount of fluid to be under pressure.
Pdf an experiment on electric power steering eps system. Pdf study of electric power steering system researchgate. Design of the auto electric power steering system controller article pdf available in procedia engineering 29. When it happens, electric power steering will move up marker to the heavier cars and maybe even trucks. The central electronic elements of todays electric power steering systems are modern 16 and 32bit mcus designed for safetycritical applications.
Also, a technician must understand how the modules and sensors work together to determine the level of assist. Ez electric power steering develops a bespoke metal mounting frame for each type of car we convert. Diagnosing power steering system failures know your parts. Its not overly noisy, but i certainly never noticed any noise coming from the steering column with hydraulic power steering. Hydraulic power steering has improved quite a bit since a man named fitts installed a system into an antique car back in 1876 the small amount of strength required to turn a steering wheel and make a modern vehicle turn with the assistance of a highpower device is a significant departure from the original.
Replacing hydraulic assist with a computercontrolled electric motor seemed like a. The future of power steering how car steering works. The automobile electric steering system is a servo control system. The main difference between the different types of pumps is the design of the fins that. Lane assist, selfparking and higher levels of selfdriving systems are all almost commonplace in the cars of today, and all of these rely heavily on the integrity of the vehicles eps. The central electronic elements of todays power steering systems are modern 32bit microcontrollers, arm controllers mcus. Echnical eports static steeringcontrol system for electric. Hydraulic power steering system it is the type of power steering system in which hydraulic system having hydraulic pump driven by the engine and hydraulic cylinders, is used to multiply the steering wheel input force which in turn reduces the efforts required to steer the front wheels of the vehicle. Information is provided on the fundamentals and inspection procedures for wheeled vehicle steering systems. Hydraulic power steering extracts power from engine, so it reduces the fuel mileage of the engine. Since the power steering pump on most cars today runs constantly, pumping fluid all the time, it wastes horsepower. Eps also enables adas features, such as lane keeping, park assist, active return to center, traffic jam assist and much more.
Some estimates predict eps systems could be installed in over 70 percent of north american vehicles by 2021 1 2. One of the coolest ideas on the drawing board is the steerbywire or drivebywire system. New electrical power steering systems wiley online library. Servicing the steering system automotive technology.
The steering system, which accurately conveys road conditions to the driver, is indispensable for safe and comfortable driving. Most of these steering systems relied on mechanisms that provided an extra mechanical advantage to make it easier. Abstract electric power steering offers greater vehicle safety by adapting variable steering ratios to human needs, filtering drive train influences and even. In most cases, electric power steering is a lot lighter to use than oldschool hydraulic systems, meaning less muscle is needed to turn the wheel. Advantages of the ephs electrically powered hydraulic steering when driving solely on motorways, there is a high power loss at the bypass valve in a conventional powerassisted steering system as a result of the high engine speed, in other words at low steering angle rates and high engine speed, the power steering pump supplies an excess. A hydraulic power steering unit consumes more energy than your car. These distinct types are explained in below diagram. Pdf control of an electric power assisted steering. Electric power steering systems eps have never been safer. The greater the power steering assist, the greater the load on the electrical system. Control of an electric power assisted steering system using refer ence model a. Different types of power steering pumps are used to power the system. Rahman encyclopedia of life support systems eolss figure 4. Electric power steering vs hydraulic power steering.
At this point, the fluid pressure in chamber a of the power cylinder increases depending on the. International journal of engineering and innovative. By applying its unique precision control based on vehicle running tests, nsk can ensure flexible management for the different input loads of various types of vehicles. Hydraulic components, including the power steering pump and hoses, should be inspected for leaks. Electronic power steering street rodder magazine hot rod. Power assisted system power steering power steering system ps10 when steering force is applied. System theoretic process analysis of electric power steering. This paper introduces the basic composition of the electric power steering system, and put forward the reasonable design. To test the system, you can test drive th e vehicle or use a scan tool to enter false vehicle speed inputs to check if the system is changing the amount of. Power steering too much physical exertion was needed for vehicles external power is only used to assist the steering effort. Furthermore, advanced steering functions are implemented in modern epas systems to improve the comfort of driving and to support vehicle functionalities.
652 483 1118 130 3 151 1492 419 1440 1189 488 77 311 376 1391 91 1069 187 394 315 40 85 529 129 669 344 713 1071 341 517 339 281 72 852 933 9 44 215 413 380 771 1270 1036 688