In addition to conventional turning assist near grip limits, the Motion Management System expands its control to include everyday driving situations such as urban driving and winding roads. The Motion Management System assists the driver in controlling the vehicle in all driving situations, such as compound and tight corners, and slippery snow-covered or wet roads.
Vehicle handling control for everyday driving
Conventional vehicles are equipped with Vehicle Stability Assist (VSA), which combines ABS, TCS, and side-slip control for oversteer and understeer, with four-wheel brake control. Through fine-grained control, VSA effectively suppresses sudden changes in vehicle behavior and provides the driver with a sense of comfort and peace of mind.
In addition, Honda has adopted Agile Handling Assist, an electronic control system that achieves smooth vehicle behavior with less steering wheel operation, making it easier to trace the desired driving line when turning.
Utilizing VSA hardware, when the driver starts to turn the steering wheel, the system predicts the yaw rate based on vehicle speed, and amount of steering and speed. If the system determines that intervention is necessary, light braking is applied to the wheels on the inside of the turn to improve the response to steering input. When the driver returns the steering wheel to drive in a straight line, the system applies the brakes on the outside wheels to counteract the previous yaw rate and quickly stabilize the vehicle.
Honda’s newly developed Motion Management System adds new front load control technology to the logic behind the existing Agile Handling Assist to expand vehicle control to everyday driving situations such as urban driving and winding roads, providing fun and safer driving in all situations.
The front load control is a new control that further improves handling stability for hybrid vehicles by increasing the weight distributed to the front wheels through integrated control of the traction motor torque and the brakes in response to the driver’s steering input. Precise control is made possible by motors that can be accurately controlled.
When this front load control is applied, the vehicle experiences a deceleration force, resulting in a slight forward-leaning pitch angle. This also slightly increases the vertical load on the front wheels, which increases the effectiveness and responsiveness of the steering wheel. This allows for a smoother entry posture toward the apex of the curve, such as when turning into a corner, and more stable followthrough.
Increase in front wheel load due to deceleration force
Front load control in action
Integrated control applied to traction motor and brake from the moment the driver turns the steering wheel
When the hybrid vehicle changes lanes or enters a turn and increases the steering wheel angle, the front load control generates a maximum deceleration force of 0.05G by applying the integrated control on traction motor torque and braking. This deceleration is a natural part of the vehicle’s behavior as it enters a turn, so smooth that the driver does not notice the system activating.
By monitoring the vehicle's condition, the system also adjusts deceleration force to allow the driver to steer safely while maintaining comfort even on rough surfaces.
Overview of front load control system
Front load control system senses the steering wheel angle input by the driver and determines the amount of deceleration to be added based on the amount and speed of turning the steering wheel. The system then applies deceleration through integrated control of the powertrain torque and brakes. This deceleration, combined with the deceleration due to steering drag force (the driving resistance from the tires) is the total deceleration force applied to the vehicle, and becomes a factor that increases front wheel load.
Another characteristic of the front load control is that it works faster than steering drag force, which results in excellent responsiveness that reacts instantaneously to steering wheel input.
Increase in deceleration and front wheel load by front load control and steering drag force
Assisting the driver in everyday driving for greater fun and peace of mind
With the Motion Management System, it feels as if the vehicle provides the cue to turn by applying the brakes slightly to increase load on the front wheels. In other words, the vehicle assists the driver with one of the tasks the driver would normally need to control.
For example, in a compound turn that becomes tighter, the vehicle may swerve outward depending on the driver's vehicle operation. In such cases, the Motion Management System will correct the steering according to how the driver increases the steering wheel angle, making it easier to trace the driver's intended driving line.
Driving in a compound turn
On tight consecutive corners common on mountain roads, the driver may not be able to complete the turn as intended depending on the situation, such as when the road surface is wet and slippery, and the vehicle may cross the center line or sway out of the lane. In the past, VSA would be activated at this point to stabilize the vehicle, but the Motion Management System provides an assist to make it easier to trace the driver's intended driving line, enabling the driver to feel greater peace of mind.
Driving through tight consecutive turns
On slippery snowy or wet roads, tires have much less grip than on dry roads, so driving even slightly too fast may result in the vehicle not turning as intended, as steering is less effective. By increasing the grip of the front tires, the Motion Management System provides a dynamic assist to manage the vehicle’s behavior in such situations. Moreover, the system also increases steering response, which enables the driver to enjoy driving with greater peace of mind.
Driving on slippery snowy or wet roads
Honda’s Motion Management System not only assists the driver in managing vehicle behavior in a wider range of situations, but increases steering response. Such solid steering feel enables the driver to feel a greater sense of reassurance. As a result, the driver can enjoy driving even more.
