While it's important to master motorcycle riding skills, it's also important to accurately grasp "what state the motorcycle is in right now," and that's exactly what the IMU does, which is equivalent to a powerful computer aid.
Modern high-end motorcycles, especially supercars, are equipped with a variety of electronics such as ride modes, traction control, ABS and semi-active suspension, among others. But for these electronic devices to work, it's important that the motorcycle itself knows exactly what the rider wants to do and what the motorcycle is doing.
First, "What does the rider want to do?" "A certain degree of judgment can be made by operating the throttle on/off (throttle position sensor), braking intensity (ABS unit), shifting gear (gear sensor), etc. However, in the past, only by knowing the speed and engine speed, the gears used, and the number of front and rear tires could we know "What is the state of the motorcycle?" For example, if there is a difference in front and rear tire rotation, you can determine whether the tire is due to braking that is about to lock (abs enable) or whether the rear wheels are idling during acceleration (enabling traction control). Then, accurate information can only be obtained when the body is driving upright and straight, then in the corner, or when there is a slope, the vehicle is not in a normal upright and straight line when there is a high risk of slippage and fall. This is where the IMU (Inertial Measurement Unit) comes into play. It is a device that measures the attitude change of a motorcycle and accurately detects the "current state of the motorcycle".
6-axis IMU It has a built-in electronic gyro sensor and accelerometer that detects pitch (rotation relative to the left and right axes), roll (rotation relative to the front and rear axes), yaw (rotation relative to the upper and lower axes) and acceleration in the back/left/right/up and down directions of the acceleration.
If the IMU detects "Roll Right Yaw Forward Pitch" and "Forward and Backward Deceleration", it will be in the right corner into the -turn state. And, if these gradually strengthen, you can tell that they are in a close state while slowing down, and if they are stable and do not change much, you can tell that they are in a corner state. If the roll changes in an upright direction from here and accelerates forward, it is ascending. If the yaw angular velocity suddenly increases during such a turn, it can be inferred that the rear wheel is slipping and swinging outward. In fact, the IMU detects motion in a more complex way, and also takes into account the difference in rotation of the front and rear tires to comprehensively determine the "current state of the motorcycle".
What are the benefits of this? For example, when the rear wheel is about to slip at the beginning of a corner, the slip can be precisely controlled with traction control to avoid slippage. In addition, with the latest electronic control equipment, the torque is no longer suppressed only by ignition cut-off and fuel injection (so that slippage and descent can be avoided), but by the computer for subtle throttle control.
In addition, to prevent lock-up when braking, not only the difference in rotation between the front and rear tires is taken into account, but also the inclination of the body and acceleration/deceleration, so that braking can be applied even at full gradient when cornering. Hence the emergence of the "curve ABS", which has changed from a conventional "safety device" to a greatly enhanced sporty configuration. In addition, the "semi-active suspension" can automatically adjust the suspension in real time to match the settings of the driving scene, which is one of the functions that the IMU can achieve, because the IMU can detect the posture and movement of the body.
The information from the IMU greatly improves the control accuracy of electronic devices such as ride mode (power mode), traction control, cornering ABS (racing ABS), wheel control, and electronically controlled suspension.
The six-axis IMU can be understood as an indispensable device for sports driving, but it seems to be useless equipment for riders who are mainly tourists and urban cycling. In fact, IMUs are more useful for inexperienced beginners.
For example, corners are more efficient than traditional ABS because it is effective even on mountain road curves in the low speed range. In addition, the "Hill Assist Function" has been implemented in cooperation with IMU, which maintains the brakes when starting on slopes and makes it easier to start. In addition, the latest "adaptive cruise control" is largely due to radar technology, but unless the IMU is able to grasp the posture and movement of the body, speed maintenance and acceleration and deceleration during corners and lane changes can be done smoothly and safely. So IMU helps a lot in terms of improving comfort and movement.