Speed planning method and system for hybrid vehicle

Abstract

The invention provides a speed planning method and system for a hybrid vehicle. According to the method and system, a deceleration area in real time is detected in a driving process, and the distance S between the hybrid vehicle and the deceleration area is obtained; a sliding distance S0 is calculated according to the current speed of the hybrid vehicle and the predicted speed of the deceleration area, and when S0 is larger than or equal to S, a driver is reminded to control the hybrid vehicle to slide; after the hybrid vehicle starts to slide, since the hybrid vehicle cannot reach the deceleration area through pure sliding at the moment, energy recovery needs to be carried out to increase deceleration. According to the method and system, an evaluation function is formulated according to an energy recovery maximization principle to calculate an optimal recovery starting moment and an optimal motor torque sequence; the motor torque of the hybrid vehicle is controlled according to the optimal motor torque sequence, and energy recovery is started at the optimal recovery starting moment, so that the drivability and the safety are ensured, energy conversion loss is reduced, and energy conservation and emission reduction effects are improved.

Description

technical field [0001] The invention relates to the technical field of new energy vehicles, in particular to a speed planning method and system for a hybrid vehicle. Background technique [0002] Hybrid vehicles generally refer to gasoline-electric hybrid vehicles, that is, vehicles driven by a mixture of fuel (gasoline, diesel) and electric energy. Hybrid vehicles have high fuel economy performance and superior driving performance. Their engines are driven by fuel, and they are driven by electric motors when starting and accelerating, so they can reduce fuel consumption and have great development prospects. [0003] 48V hybrid vehicles have gradually become the mainstream in the hybrid vehicle market due to their good energy-saving and emission-reduction performance and relatively low cost. The reason why 48V hybrid vehicles can effectively reduce energy consumption is that on the one hand, it improves energy conversion efficiency through a reasonable energy distribution s...

AI Technical Summary

Problems solved by technology

However, due to the structural characteristics of hybrid vehicles, the engine will also be dragged backward during the energy recovery process. Therefore, there will be a loss of engine backward drag work. In order to reduce this part of energy loss, it is hoped to start energy recovery as late as possible

However, the later the energy is recovered, the slower the vehicle speed will drop, especially when the initial vehicle speed is high, it will take a longer braking distance to drop to the specified speed

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