Make motorcycles better and safer through innovative developments and also enhance the joy of motorcycle riding – that’s for decades one of the core competencies of BMW motorcycle. As a technology leader BMW Motor presents new solutions with high impact numbers that are usually only a short time later, an essential part of the Series motorcycles. Now, today announced a new development stage: the semi-active suspension control system Dynamic Damping Control, shortly DDC.
BMW motorcycle – chassis control systems and innovation
In 1986, BMW began with the introduction of the Paralever rear swingarm chassis a technical milestone that provided a much better rear suspension and power transmission. In 1993, the then-new Boxer series the first time a front wheel series in which the tasks of the suspension and damping of which separates the wheel location – the Telelever. Another revolutionary step forward in the chassis technology introduced in 2005, launched an extremely rigid Duolever front suspension dar.
Even with the drive control could benefit from the motorcyclist early breakthrough innovations. 1988 BMW Motor presented with the introduction of ABS in the BMW, the first standard anti-lock braking system for motorcycles K1. Since 2007, prevents the traction control ASC (Automatic Stability Control) in an uncontrolled manner by turning the rear wheel. There followed in 2009, the dynamic traction control (DTC Dynamic Traction Control), which involved in the regulation of the drive slip for the first time with a production bike and the driven inclined.
In terms of chassis control systems, BMW Motor also presented again and again.Thus did in 2004 with the electronically adjustable suspension ESA (Electronic Suspension Adjustment) for the first time by the driver via a button adjustable spring elements in series production of motorcycles catchment. The follow-up system in 2009, ESA II went a step further and allowed for the first time, to vary the spring rate.
The Next Step: Semi-active suspension control
The logical next step in the development of chassis and control systems is emerging clearly. With the automatic adjustment of the spring elements to different operating conditions such as changing road conditions or specific maneuvers the next evolutionary stage is reached. BMW Motor achieved it in the Dynamic Damping Control DDC.
Analog technologies in the BMW cars range, for example in the BMW M3, BMW M5, have been successfully used. This resulted in valuable synergy effects for the in-house development . The challenge was to adapt the system to the requirements of the motorcycle-driving physics, and integration into the relevant control systems.
Evolution: From ESA II DDC
Significant progress in adapting to different load conditions and road conditions highlighted BMW motorcycle with the introduction of the electronically adjustable suspension (ESA II Electronic Suspension Adjustment). It allows the driver apart from the damping of the two spring legs of Duolever / Telelever front and Paralever rear, the spring rate of the rear shock absorber so to speak, and the “hardness” of the spring easily set by pushing a button. The selectable curves for springs and dampers allow unprecedented customization to tune the suspension to the road conditions as well as the loading and excellent operator comfort.
In connection with the three possible Coordination modes “Comfort”, “Normal” and “Sport” ESA II opened up a new dimension of stability at the best response in all driving and load conditions. ESA II was in this form, the motorcycle world’s first electronic suspension adjustment system with such far-reaching adjustment. With the aim of achieving an even more stable and thus safer driving behavior, the Dynamic Damping Control DDC again goes a step further. When DDC is a semi-active suspension system that automatically responds to both maneuvers such as braking, accelerating or cornering and on the road surface and the attenuation using sensory parameters determined via electrically controlled proportional damper valves situational properly adjusted.
The DDC is connected via the CAN bus with the DTC traction control and ABS. The system detects any control activities of the other systems, and controls the attenuation adaptively according to the requirements. Depending on whether it is a one-or from the process, there is a separate control of the train and rebound damping. The adjustment of the damping via an electrically controlled proportional valve, damper, in which an annular gap and thus the flow area of ??the damper oil is changed. By inversely proportional change of velocity and pressure, the damping force is adjusted within a few milliseconds to the new realities.
In the Dynamic Damping Control DDC come ESA II as opposed to no curves, but maps are used to provide within a defined range, the optimum damper settings. About three selectable touch of a button mapping for the basic votes “Comfort”, “Normal” and “Sport”, this system allows the rider to ride with its individually preferred vote. As of ESA II is already known, the selected voting will be displayed in the instrument cluster. ESA II is analogous to the DDC, a variable spring rate.
DDC mode of action in driving
The advantages are the basis of some illustrative examples of specific driving situations quickly become clear. Before starting a journey is with the ignition system first and check the flow of information from engine control, ABS control unit, sensor box (DTC) and the travel sensors for Dynamic Damping Control (DDC) is activated control device. In combination with this instrument, a corresponding indication.
- When starting up the valves on the front and rear damper from an adjustable minimum speed can be controlled only small (sampling). The driver accelerates, for example at the exit is actuated, the valve of the rear shock absorber due to the changed dynamic wheel load and the drive torque more. Only after reaching the target speed, the control of the valve goes to its initial value (less than energized during the start) back. Here is the information flow from the engine throttle control to the DDC controller and from there to the damper valves.
- When driving through a curve, the change of control of each damper valves – starting from the low current feed – increases with increasing angle to the apex. When restoration of the vehicle between the two curves is the control of each damper valves with continuously decreasing tilt back to the original Energization value determination. Once the driver initiates the second curve, which takes control again proportional to the tilt angle from the apex and again. Here is the information flow from the sensor box (DTC) to the DDC controller and from there to the damper valves.
- When braking – about a railroad crossing – which takes control of the front damper valve in proportion to the delay, so that during braking, the damping forces and thus the driving stability can be increased. The Dynamic Damping Control DDC considered here both the dynamic phase of the braking process to reach steady deceleration and wheel load and the subsequent static phase.
By reaching the appropriate speed – here for driving over the railway crossing – does the current flow, and thus the control back to the base value. Here, the information flow is from the hand brake on the handlebar to the ABS pump and from there via the DDC controller to the valves. When crossing the railway crossing – here representing all kinds of bumps in the road – the valves of the front and rear damper can be controlled in proportion to the respective compression travel (energized). The information flow is carried out starting from the front and rear suspension travel sensors on the DDC controller to the valves. If the motorcycle is then brought to a standstill, the valves are initially activated as already described in the braking process. Only after reaching standstill and the current supply is turned off so that controlling the valves.
Advantages of the Dynamic Damping Control DDC
The system evaluates in the shortest time from a variety of situational information and selecting the right one, highly precise wheel alignment. This results in a significant increase in active driving safety, convenience – and not least in driving pleasure. The suspension damping system DDC will hold in the near future entrance into the first production models of BMW motorcycles.
