Active Stabilizer Suspension System
Encyclopedia
Active suspension
Active or adaptive suspension is an automotive technology that controls the vertical movement of the wheels with an onboard system rather than the movement being determined entirely by the road surface...
system developed by Toyota Motor Corporation
Toyota Motor Corporation
, , , commonly known simply as Toyota and abbreviated as TMC, is a multinational automaker headquartered in Toyota, Aichi, Japan. In 2010, Toyota Motor Corporation employed 317,734 people worldwide, and was the world's largest automobile manufacturer by production.The company was founded by...
for its high-end vehicles including Lexus
Lexus
is the luxury vehicle division of Japanese automaker Toyota Motor Corporation. First introduced in 1989 in the United States, Lexus is now sold globally and has become Japan's largest-selling make of premium cars. The Lexus marque is marketed in over 70 countries and territories worldwide, and has...
models. By altering stabilizer bar stiffness, this system acts to reduce body tilt during cornering, keeping the vehicle more level during turns and improving handling, as opposed to the natural tendency of a vehicle to roll due to the lateral forces experienced during high-speed maneuvering. The active stabilizer system relies on vehicle body sensors and electric motors. The first production usage of this system occurred with the 2007 Lexus GS
Lexus GS
The Lexus GS is a series of mid-size luxury sports sedans / executive cars sold by Lexus since 1993. Designed to fill the gap between the ES and LS, and to provide Lexus with a performance sedan to compete in the mid-luxury class, three generations of the GS have been produced to date...
sport sedan, followed by the 2008 Lexus LS 600h luxury sedan. The development of APSSS is claimed to be the world's first electric active stabilizer system.
How it works
The APSSS utilizes sensors for steering wheelSteering wheel
A steering wheel is a type of steering control in vehicles and vessels ....
speed, steering angle, along with yaw and acceleration
Acceleration
In physics, acceleration is the rate of change of velocity with time. In one dimension, acceleration is the rate at which something speeds up or slows down. However, since velocity is a vector, acceleration describes the rate of change of both the magnitude and the direction of velocity. ...
/deceleration sensors. These sensors are tied to an electronic control unit
Electronic control unit
In automotive electronics, electronic control unit is a generic term for any embedded system that controls one or more of the electrical systems or subsystems in a motor vehicle....
(ECU), which in turn connects with actuator
Actuator
An actuator is a type of motor for moving or controlling a mechanism or system. It is operated by a source of energy, usually in the form of an electric current, hydraulic fluid pressure or pneumatic pressure, and converts that energy into some kind of motion. An actuator is the mechanism by which...
s consisting of 46V DC brushless motors and reduction mechanisms. Mounted with the vehicle suspension
Suspension (vehicle)
Suspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose — contributing to the car's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants...
stabilizer bars, each reduction mechanism houses a wave generator
Electrical generator
In electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
, flexible gear
Gear
A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine....
, and circular gear.
The system is activated when the vehicle enters a high-speed turn, and the sensors register vertical, longitudinal, and transverse forces which contribute to body lean and additional movements. Along with steering data, these are sent to the ECU where they are processed, with the forces necessary to counteract body roll movements calculated. Corrective instructions are then sent to the suspension motors and reduction mechanisms. The reduction mechanism gears activate to adjust suspension rigidity, torquing the stabilizer bars, and thus increasing sway resistance and reducing body roll movements. Developed jointly with Aisin, APSSS engineers found that compared with prior hydraulically actuated active suspension systems, which rely on hydraulic servomechanism
Servomechanism
thumb|right|200px|Industrial servomotorThe grey/green cylinder is the [[Brush |brush-type]] [[DC motor]]. The black section at the bottom contains the [[Epicyclic gearing|planetary]] [[Reduction drive|reduction gear]], and the black object on top of the motor is the optical [[rotary encoder]] for...
s, the electric APSSS offered a faster response time (within 20 milliseconds) and reduced energy consumption characteristics.
Vehicles
Vehicles that have offered Active Power Stabilizer Suspension System (APSSS) to date, listed by model yearModel year
The model year of a product is a number used worldwide, but with a high level of prominence in North America, to describe approximately when a product was produced, and indicates the coinciding base specification of that product....
(system was offered as an option):
- 2007 Lexus GS 430
- 2007 Lexus GS 450h
- 2008 Lexus GS 460
- 2008 Lexus LS 600h
- 2008 Lexus LS 600h L
- 2010 Lexus RX 450h
See also
- Active suspensionActive suspensionActive or adaptive suspension is an automotive technology that controls the vertical movement of the wheels with an onboard system rather than the movement being determined entirely by the road surface...
- Height adjustable suspensionHeight adjustable suspensionHeight adjustable suspension is a feature of certain automobile suspension systems that allow the motorist to vary the ride height or ground clearance. This can be done for various reasons including giving better ground clearance over rough terrain, a lower ground clearance to improve fuel economy...
- Lexus Kinetic Dynamic Suspension SystemKinetic Dynamic Suspension SystemFor other articles named KDSS, see KDSS .The Kinetic Dynamic Suspension System technology was employed initially in the Lexus GX 470, and subsequently the 200 Series Toyota Land Cruiser. The system was invented and developed by Kinetic Pty Ltd, a small R&D company based in Dunsborough, Western...
(KDSS) - Self-levelling suspensionSelf-levelling suspensionSelf-levelling refers to an automobile suspension system that maintains a constant ride height of the vehicle above the road, regardless of load....