Active suspension is a system of improving driver’s operation stability and passengers’ level of comfort by detecting vibrations generated in the vehicle during cruising along with vehicle tilt and centrifugal force during cornering by using inertial sensors and appropriately controlling suspension.
The 6-axis 1-chip sensor has superior orthogonality and self-diagnosis function in each axis. With functional safety and good vibration characteristics and temperature characteristics, the Panasonic 6in1 sensor used for active suspension can reduce the number of the required sensors and space for storing modules while contributing to the improvement of the freedom of installation position.
Application key points of the 6in1 sensors in active suspension vibration control
- 6-axis detection capability by a single chip enables detection of vehicle vibration and tilt during cruising, thereby reducing the number of required sensors from the previous system as well as saving installation space and increasing freedom of the installation position
- Enables appropriate suspension control even in an environment with severe vibration and tilt
- Self-diagnosis function on all 6 axes with grade 1 (-40°C to +125°C) functional safety conforming to ASIL-B(D) temperature characteristics
Effect of adopting 6in1 sensors in active suspension
Effect (1): Compact single-chip 6-axis detection capability reduces the sensor count, contributes to space reduction and enables central control of the system
Previous active suspension required installation of an inertial sensor near each suspension point to detect vehicle vibration and tilt. Because the Panasonic 6in1 sensor consists of 3-axis acceleration and 3-axis angular acceleration detection MEMS in a single chip, several pieces of sensor required in the previous system can be replaced with a single sensor by reducing the number of sensors as well as the space required for installation. Computation of output data of acceleration and angular speed of each axis enables detection of vehicle vibration and tilt even in a position apart from each suspension point, improving the freedom of the installation position of the sensor and module. In addition, improved inter-axis orthogonality of 6 axes contributes to more accurate detection of vehicle condition.
【Point】
- Detection of 6-axis by a compact single chip contributes to the reduction of sensor count and installation space
- Detection capability of vehicle vibration and tilt even in a position apart from the suspension improves the freedom of the installation position
Effect (2): Appropriate suspension control is possible in an environment with violent vibration and tilting
Because the Panasonic 6in1 sensor is designed assuming a severe operating environment of two-wheel vehicles, construction equipment, etc. In a vibration test shown in the figure, good vibration characteristics are shown for a wide range of frequencies. Even if a spike appears on obtained data, identification is possible if it is an abnormal signal using the SM (Safety Mechanism), so that accurate detection of acceleration and angular speed is possible even in an environment generating severe vibration or tilt. When a sensor is used in active suspension and strong vibration is generated from unpaved road surface or steep tilt is generated while cornering a sharp curve, appropriate suspension control is possible for maintaining the rider’s comfort.
【Point】
- Even in an environment with severe vibration and tilt, accurate detection of vibration and tilt is possible, thereby enabling appropriate suspension control
- ・Vibration frequency
- ： 0.5kHz⇒20kHz
- ・Vibration amplitude
- ： 7G
- ・Measurement attitude
- ： Z_+1G attitude（AccZ only X+1G posture to avoid disturbance factors ）
- ・Filter setting
- ： 60Hz
- ※Measurement attitude：X+1G
Effect (3): All of the 6 axes are equipped with a self-diagnosis function and conform to the functional safety standard ASIL-B(D). Grade 1 temperature characteristics
Active suspension as a system is required to comply with functional safety standards ASIL-B or C. Panasonic's 6in1 sensors are equipped with a self-diagnosis function in all of the 6 axes and conform to ASIL-B(D) as a sensor, thereby capable of satisfying the functional safety requirements. In addition, the 6in1 sensor conforms to the reliability test AEC-Q100 and operation within temperature grade 1 (-40°C to +125°C) is warranted, enabling stable detection of acceleration and angular speed in both cold and hot temperature environments.
【Point】
- All of the 6 axes are equipped with a self-diagnosis function and conform to functional safety standard ASIL-B(D)
- Grade 1 (-40°C to +125°C) temperature characteristics
