EHPS (electric hydraulic power steering system) of new energy bus and control method of EHPS

Abstract

The invention discloses an EHPS (electric hydraulic power steering system) of a new energy bus and a control method of the EHPS. The EHPS comprises a vehicle speed detection unit, a vehicle control unit, a DC (direct current) and AC (alternating current) inversion unit and a power steering pump which are connected in sequence, wherein the power steering pump is provided with a steering pump control unit and a steering pump current detection unit. The EHPS comprises the vehicle speed detection unit, the vehicle control unit, the DC and AC inversion unit and the power steering pump, compared with existing patents and control strategies, cost increase caused by additional electrical components is prevented, intelligent control of steering assisted power is realized, and the EHPS has universal applicability under the configuration of the existing new energy bus and can realize the scale effect. When a vehicle is in a parking state and the steering pump shuts down, idling power of the steering pump and unnecessary loss are reduced with the adoption of the EHPS; different steering assisted power at different vehicle speeds and idling energy loss of the steering pump when steering assisted power is not required in straight traveling are both taken into consideration, and energy is saved by 60% or higher.

Description

technical field [0001] The invention relates to a new energy bus, in particular to an electrohydraulic power steering system and a control method for a new energy bus. Background technique [0002] Since 2010, the new energy vehicle industry has developed rapidly, and the technological progress of domestic pure electric vehicles has been particularly obvious. At present, a major obstacle to the development of pure electric vehicles is the driving range. Improving the efficiency of energy utilization and reducing unnecessary energy waste is very effective and in line with my country's basic national policy of energy conservation and emission reduction under the current technical capabilities. [0003] Passenger cars mostly use hydraulic power steering system, while traditional hydraulic power steering only has a single power assist characteristic. On the basis of the power steering system, an electronic control device is added to adjust the power steering according to the ve...

AI Technical Summary

Problems solved by technology

[0003] Passenger cars mostly use hydraulic power steering system, while traditional hydraulic power steering only has a single power assist characteristic. On the basis of the power steering system, an electronic control device is added to adjust the power steering according to the vehicle speed, and the steering power of high and low speeds is coordinated. However, the EHPS system needs to add steering wheel speed sensor, electronic control unit (ECU) and torque sensor and other equipment, and the cost will be higher. Increased by tens of thousands of yuan or more

[0004] There is a direct relationship between hydraulic power steering and the flow rate. During the working life of the vehicle, there are states such as neutral, straight, and steering, and the requirements for power assist are relatively low in neutral and straight. Most of the steering power control strategies at this stage only Considering the change of power assist with the speed of the vehicle, it does not take into account the loss of energy consumption when there is no need for steering, such as neutral gear and straight driving

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