CN-122029090-A - Control device for electric vehicle

Abstract

A control device for an electric vehicle is provided with a region-by-region estimated road surface friction coefficient setting unit that estimates and sets a region-by-region road surface friction coefficient based on travel environment information, a slip suppression control unit that is provided with a slip vibration detection unit that detects slip vibration from motor vibration, and a motor-estimated road surface friction coefficient setting unit that estimates and sets a road surface friction coefficient based on the detected slip vibration, and is provided with a deviation calculation unit that calculates a deviation of the region-by-region road surface friction coefficient, a reaction force instruction value setting unit that sets a reaction force instruction value that generates a strong reaction force when the deviation exceeds a first threshold value as compared with when the deviation is lower than the first threshold value, and a reaction force instruction unit that outputs an instruction signal of the reaction force instruction value to the reaction force application unit when the road surface friction coefficient is equal to or lower than a second threshold value.

Inventors

• NAKAHIRA SHINICHIRO
• SHINODA SHINJI
• Kimura Junshu
• FUJII YUTO
• Naoto Chiba
• MORIMURA YOSHIO
• Sato satoki
• TERADA TAKURO
• Wei Kuanhe
• Shan Xingjin
• Hinnosuke Masuda

Assignees

• 株式会社斯巴鲁

Dates

Publication Date

20260512

Application Date

20231025

Claims (5)

1. 1. A control device for an electric vehicle is characterized by comprising: A running environment detection unit that detects a running environment in front of the electric vehicle; A vibration detection unit that detects motor vibrations generated at the rotational speed of a drive motor mounted on the electric vehicle; a reaction force applying portion that applies a reaction force to an operation portion operated by a driver; A per-region estimated road surface friction coefficient setting unit that estimates and sets a per-region road surface friction coefficient based on the running environment information detected by the running environment detection unit; slip control unit, and A reaction force indicating portion for indicating the reaction force, The slip suppression control unit includes: a slip vibration detecting unit for detecting slip vibration based on the motor vibration detected by the vibration detecting unit, and A motor estimated road surface friction coefficient setting unit that estimates and sets a road surface friction coefficient based on the slip vibration when the slip vibration is detected by the slip vibration detecting unit, The reaction force instruction unit is provided with: a deviation calculating unit that calculates a deviation of the road surface friction coefficient for each region detected by the road surface friction coefficient setting unit for each region; A reaction force instruction value setting unit that compares the deviation of the road surface friction coefficient for each region calculated by the deviation calculating unit with a first threshold value, and sets a reaction force instruction value that generates a strong reaction force when the deviation exceeds the first threshold value, compared with when the deviation is lower than the first threshold value, and And a reaction force command unit configured to output a command signal of the reaction force command value set by the reaction force command value setting unit to the reaction force applying unit when the road surface friction coefficient set by the motor estimated road surface friction coefficient setting unit is equal to or smaller than a second threshold value.
2. 2. The control device for an electric vehicle according to claim 1, wherein, The control device of an electric vehicle further has a steering wheel operation detection portion that detects an operation of the steering wheel by the driver, The reaction force instruction unit further includes a second threshold setting unit that sets the second threshold to a higher value when the steering device operation is detected by the steering wheel operation detection unit than when the steering wheel operation is not detected.
3. 3. The control device for an electric vehicle according to claim 1, wherein, The control device for an electric vehicle further includes: A vehicle position detection unit that detects a current position of the electric vehicle; An environment information acquisition unit that acquires surrounding environment information of the electric vehicle based on the current position of the electric vehicle detected by the vehicle position detection unit, and An estimated road surface friction coefficient initial value setting unit that sets an initial value of an estimated road surface friction coefficient based on the surrounding environment information acquired by the environment information acquisition unit, The estimated road surface friction coefficient per region setting unit corrects the estimated road surface friction coefficient per region using the initial value of the estimated road surface friction coefficient set by the estimated road surface friction coefficient initial value setting unit, and sets a new road surface friction coefficient per region.
4. 4. The control device for an electric vehicle according to claim 3, wherein, The surrounding environment information is at least one of road map information and weather information.
5. 5. The control device for an electric vehicle according to claim 1, wherein, The operation unit is at least one of an accelerator pedal and a brake pedal.

Description

Control device for electric vehicle Technical Field The present invention relates to a control device for an electric vehicle having a function of determining the presence or absence of occurrence of a slip. Background When the driving force applied to the tires of the driving wheels (referred to as "driving tires") exceeds the grip force from the road surface (referred to as "road surface grip force") applied to the driving tires, the running vehicle slips. As shown in fig. 7, the driving force P of the driving tire (front wheel in the drawing) in the vehicle M is represented by P=T/r ...(1) And (5) obtaining. Here, T is torque, r is the effective radius of the driving tire. In addition, the road surface grip force F is determined by F=μ·Wf ...(2) And (5) obtaining. Here, μ is the road surface friction coefficient, wf is the vehicle body weight applied to the driving tire (front wheel). Incidentally, in FIG. 7, W is the total weight of the vehicle body, wr is the weight of the vehicle body applied to the driven tire (rear wheel). Therefore, as shown in fig. 8, traveling control can be relatively easily performed on a dry road pavement in a relationship (p≤f) in which the driving force P does not exceed the road surface grip force F. If the relation of P≤F is maintained all the time, running can be continued without occurrence of slip. On the other hand, since the road surface grip force F of the tire on the unpaved road is lowered, a relationship of P > F is liable to occur. Therefore, it is difficult to travel on an unpaved road without slipping. Even if the vehicle M is an electric vehicle represented by an Electric Vehicle (EV), a Fuel Cell Vehicle (FCV), and a Hybrid Electric Vehicle (HEV), slip can be prevented from occurring if the vehicle is driven while maintaining the relationship of p≤f at all times. The driving motor of an electric vehicle often controls the driving force by vector control. Vector control separates a current flowing through a motor into a current component (torque current component) that generates torque and a current component (flux current component) that generates magnetic flux in a rotor, and controls each independently. Therefore, the driving force P for driving the tire can be estimated at high speed from the torque current component flowing through the motor. On the other hand, when the driving tire is idling (slipping), the motor torque fluctuates, and high-frequency vibrations (slip vibrations) occur in the rotational speed of the motor. The road surface μ can be estimated from the slip vibration. In addition, when slip vibration is detected, it can be estimated that the grip of the driving tire is relatively lowered. As is clear from the above expression (2), when the vehicle body weight Wf is made constant, the road surface grip F of the tire is determined by the road surface μ. For example, japanese patent application laid-open No. 2013-112192 discloses a technique in which, when slip of the vehicle is detected from a difference between the rotational speed of the driving wheel and the rotational speed of the driven wheel, a reaction force control device applies a reaction force to an accelerator pedal, and notifies the driver of the occurrence of slip. However, as shown in fig. 8, the road surface condition of the unpaved road is not the same, and there are various local conditions such as gravel road, sand, mud, etc. The coefficient of friction varies depending on the road surface condition. Further, there are branches having different friction coefficients on the road surfaces where the left and right driving wheels are in contact. In the technique disclosed in japanese patent application laid-open No. 2013-112192, when the reaction force control device detects slip, a reaction force against the accelerator pedal is set irrespective of a change in the actual road surface friction coefficient. Therefore, it is difficult to accurately notify the driver of the occurrence of the slip. The present invention has been made in view of the above circumstances, and an object thereof is to provide a control device for an electric vehicle that can accurately notify a driver of occurrence of a slip. Disclosure of Invention Technical proposal An aspect of the present invention relates to a control device for an electric vehicle, including a running environment detection unit that detects a running environment in front of the electric vehicle, a vibration detection unit that detects motor vibration generated at a rotation speed of a drive motor mounted on the electric vehicle, a reaction force application unit that applies a reaction force to an operation unit operated by a driver, a per-region estimated road surface friction coefficient setting unit that estimates and sets a road surface friction coefficient for a per-region based on the running environment information detected by the running environment detection unit, a slip suppression control unit that includes a slip vibra