Slope-holding auxiliary method and slope-holding auxiliary system for new energy automobile

Abstract

The invention discloses a slope-holding auxiliary method and system for a new energy automobile, and belongs to the technical field of new energy automobiles, and the method comprises the steps that a vehicle control unit (VCU) judges whether a brake state signal of the automobile is set or not and judges whether the automobile is in a stopped state or not, and if the brake state signal is set and the automobile is in the stopped state, the vehicle is stopped; if the vehicle meets a first preset condition or a second preset condition, the vehicle control unit (VCU) sets an enabling flag bit of the hill-holding auxiliary function, the motor control unit (MCU) judges whether the vehicle meets the first preset condition or the second preset condition, if yes, the motor control unit (MCU) sets an enabling signal of the hill-holding auxiliary function, the motor control unit (MCU) enters hill-holding assistance, and if not, the motor control unit (MCU) starts hill-holding assistance. And the motor controller (MCU) judges whether the motor controller (MCU) meets the condition of quitting the hill-holding assistance or not, and if yes, the motor controller (MCU) quits the hill-holding assistance. According to the invention, the driver can be assisted in hill parking and starting, and the effect of assisting the driver in hill parking and starting is good.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and in particular, relates to a hill-holding assist method and a hill-holding assist system for new energy vehicles. Background Art

[0002] As the technology and functional requirements of new energy vehicles become more and more comprehensive, the vehicle system is becoming more and more complex, which leads to an increase in the cost of vehicle development. The hill-holding assist function is basically a necessary function for new energy vehicles. At present, there are two main methods for implementing the hill-holding assist function, one is the ESP solution, and the other is to use electric drive zero speed control. Among them, the ESP solution is comprehensive and effective, but the cost is increased. In addition, the use of electric drive zero speed control function is low-cost, but the hill-holding assist function currently used in the industry is not effective, and it is easy to fail to fail, the slope sliding distance is long, and the hill-holding function is triggered by mistake, affecting the normal use of other functions.

[0003] Patent CN108189841A discloses a method and device for intelligent hill-holding of a vehicle, the method comprising: obtaining vehicle operating status information, wherein the vehicle operating status information at least comprises: vehicle reverse speed information, vehicle throttle status information and vehicle gear information; when the vehicle operating status information satisfies preset conditions, controlling the vehicle to execute a hill-holding mode.

[0004] However, the technology disclosed in the above patent causes the motor to be continuously stalled for a long time when the motor is stationary on a slope, which has the risk of reducing the service life of the motor. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a hill-holding assist method and a hill-holding assist system for a new energy vehicle in view of the deficiencies in the prior art, so as to achieve the purpose of assisting the driver in holding and starting on a slope.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The present invention provides a hill-holding assist method for a new energy vehicle, the method comprising the following steps:

[0008] S1: The vehicle controller (VCU) determines whether the vehicle's brake status signal is set. If so, it enters S2, if not, it enters S9;

[0009] S2: The vehicle control unit (VCU) determines whether the vehicle is in a stopped state. If so, it enters S3; if not, it enters S9;

[0010] S3: The vehicle control unit (VCU) sets the enable flag of the hill-holding assist function;

[0011] S4: The motor controller (MCU) receives the hill-holding assist enable signal from the vehicle control unit (VCU);

[0012] S5: The motor controller (MCU) determines whether the vehicle meets the first preset condition or the second preset condition. If yes, the process proceeds to S6; if no, the process proceeds to S9;

[0013] S6: The motor controller (MCU) enters the hill-holding assist function;

[0014] S7: The motor controller (MCU) determines whether the motor controller (MCU) meets the conditions for exiting the hill-holding assist function. If so, the process proceeds to S8; if not, the process proceeds to S6;

[0015] S8: The motor controller (MCU) exits the hill-holding assist function;

[0016] S9: End.

[0017] Further, in S2, when the vehicle controller (VCU) determines that the speed of the motor is less than the first preset speed and the duration is not less than the first preset time, the vehicle controller (VCU) determines that the vehicle is in a stopped state.

[0018] Furthermore, the first preset condition is that the gear position of the vehicle is the driving gear and the rotation speed of the motor is less than the second preset rotation speed.

[0019] Furthermore, the second preset condition is that the gear position of the vehicle is the reverse gear and the rotation speed of the motor is greater than the third preset rotation speed.

[0020] Further, in S7, after the motor controller (MCU) enters the hill-holding assist function, the motor controller (MCU) implements the hill-holding assist function by controlling the motor to zero speed. The hill-holding assist function is maintained for a second preset time each time, and the motor controller (MCU) enters the hill-holding assist function three times in succession.

[0021] Furthermore, the condition for the motor controller (MCU) to exit the hill-holding assist function is that the vehicle controller (VCU) resets the enable flag of the hill-holding assist function or the vehicle gear position changes or the motor controller (MCU) has entered the hill-holding assist function three times in a row.

[0022] Furthermore, the first preset rotation speed is 10 revolutions per minute; and the first preset time is 100 milliseconds.

[0023] Furthermore, the second preset time is 20 seconds.

[0024] The present invention also provides a hill-holding assist system for a new energy vehicle, comprising a vehicle control unit (VCU) and a motor control unit (MCU), wherein the vehicle control unit (VCU) is connected to the motor control unit (MCU).

[0025] The hill-holding assist method and the hill-holding assist system of the present invention have the following advantages:

[0026] (1) The hill-holding assist method and the hill-holding assist system of the present invention can assist the driver in holding and starting on a slope, and the effect of assisting the driver in holding and starting on a slope is good and the cost is low.

[0027] (2) The hill-holding assist method and the hill-holding assist system of the present invention can enable the vehicle to enter the hill-holding assist function quickly, and can effectively avoid false triggering of the hill-holding assist function under the conditions of emergency braking and dynamic gear shifting of the vehicle, which is safe and reliable.

[0028] (3) The hill-holding assist method and the hill-holding assist system of the present invention can improve the problems of failure of the vehicle's hill-holding assist function, false triggering, and long sliding distance. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] This specification includes the following drawings, which show the following contents:

[0030] Figure 1 It is a flowchart of a hill-holding assist method for a new energy vehicle of the present invention;

[0031] Figure 2 The present invention is a logic structure block diagram of a hill-holding assist system for a new energy vehicle.

[0032] Explanation of the reference numerals: 1. Vehicle Control Unit (VCU); 2. Motor Control Unit (MCU). DETAILED DESCRIPTION

[0033] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and facilitating their implementation.

[0034] Figure 1 The present invention is a flowchart of a method for assisting a new energy vehicle on a hill, the method comprising the following steps:

[0035] S1: The vehicle controller (VCU) 1 determines whether the vehicle's brake status signal is set. If so, it enters S2, if not, it enters S9; that is, the corresponding Figure 1Specifically, firstly, the vehicle controller (VCU) 1 determines whether the brake status signal of the vehicle is set. If the vehicle controller (VCU) 1 determines that the brake status signal of the vehicle is set, it enters S2. If the vehicle controller (VCU) 1 determines that the brake status signal of the vehicle is not set, it enters S9.

[0036] S2: The vehicle controller (VCU) 1 determines whether the vehicle is in a stopped state. If so, it enters S3; if not, it enters S9; Figure 1 Specifically, when the vehicle controller (VCU) 1 determines that the brake status signal of the vehicle is in the set state, the vehicle controller (VCU) 1 will determine whether the vehicle is in a stopped state. If the vehicle controller (VCU) 1 determines that the vehicle is in a stopped state, it enters S3. If the vehicle controller (VCU) 1 determines that the vehicle is not in a stopped state, it enters S9.

[0037] When the vehicle controller (VCU) 1 determines that the motor speed is less than the first preset speed and the duration is not less than the first preset time, the vehicle controller (VCU) 1 determines that the vehicle is in a stopped state, otherwise, the vehicle controller (VCU) 1 determines that the vehicle is not in a stopped state. The first preset speed is 10 revolutions per minute and the first preset time is 100 milliseconds.

[0038] S3: The vehicle controller (VCU) 1 sets the enable flag of the hill-holding assist function; Figure 1 Specifically, when the vehicle controller (VCU) 1 determines that the brake status signal of the vehicle is set and the vehicle is in a stopped state, the vehicle controller (VCU) 1 sets the enable flag of the hill-holding assist function as a necessary condition for the motor controller (MCU) 2 to enter the hill-holding assist function.

[0039] S4: The motor controller (MCU) 2 receives the hill-holding assist enable signal from the vehicle controller (VCU) 1; Figure 1 Specifically, when the vehicle controller (VCU) 1 sets the enable flag of the hill-holding assist function, the vehicle controller (VCU) 1 sends the enable signal of the hill-holding assist function to the motor controller (MCU) 2, and the motor controller (MCU) 2 receives the hill-holding assist enable signal from the vehicle controller (VCU) 1.

[0040] S5: The motor controller (MCU) 2 determines whether the vehicle meets the first preset condition or the second preset condition. If so, it enters S6; if not, it enters S9; that is, corresponding Figure 1Specifically, after the motor controller (MCU) 2 receives the hill-holding assist enable signal sent by the vehicle controller (VCU) 1, the motor controller (MCU) 2 determines whether the vehicle meets the first preset condition or the second preset condition. If the motor controller (MCU) 2 determines that the vehicle meets the first preset condition or the vehicle meets the second preset condition, it enters S6. If the motor controller (MCU) 2 determines that the vehicle neither meets the first preset condition nor the second preset condition, it enters S9.

[0041] The first preset condition is that the gear of the vehicle is the driving gear and the speed of the motor is less than the second preset speed; the second preset condition is that the gear of the vehicle is the reverse gear and the speed of the motor is greater than the third preset speed. The second preset speed is -10 rpm and the third preset speed is 10 rpm.

[0042] S6: Motor controller (MCU) 2 enters the hill-holding auxiliary function; Figure 1 S6 in the figure. Specifically, after the vehicle controller (VCU) 1 sets the enable flag of the hill-holding assist function, and when the motor controller (MCU) 2 determines that the vehicle meets the first preset condition or the vehicle meets the second preset condition, the motor controller (MCU) 2 sets the hill-holding assist function enable signal, and the motor controller (MCU) 2 enters the hill-holding assist function. Thus, the vehicle enters the hill-holding assist function quickly.

[0043] Among them, after the motor controller (MCU) 2 enters the hill-holding assist function, the motor controller (MCU) 2 realizes the hill-holding assist function by controlling the motor to zero speed, and the hill-holding assist function is maintained for a second preset time each time, and the motor controller (MCU) 2 enters the hill-holding assist function three times in succession. Among them, the second preset time is 20 seconds. In this way, it can assist the driver to hold and start on a slope, and the effect of assisting the driver to hold and start on a slope is good and the cost is low.

[0044] S7: The motor controller (MCU) 2 determines whether the motor controller (MCU) 2 meets the conditions for exiting the hill-holding assist function. If so, it enters S8; if not, it enters S6; that is, corresponding to Figure 1 Specifically, after the motor controller (MCU) 2 enters the hill-holding assist function, the motor controller (MCU) 2 determines whether the motor controller (MCU) 2 meets the conditions for exiting the hill-holding assist function, and if so, enters S8, and if not, enters S6.

[0045] Among them, the condition for the motor controller (MCU) 2 to exit the hill-holding assist function is that the vehicle controller (VCU) 1 resets the enable flag of the hill-holding assist function or the vehicle gear position changes or the motor controller (MCU) 2 has entered the hill-holding assist function three times in a row. Among them, when the vehicle controller (VCU) 1 determines that the speed of the motor is greater than 200rpm or determines that the torque command of the vehicle controller (VCU) 1 is greater than the hill-holding assist value of the motor controller (MCU) 2 or determines that the hill-holding assist enable signal of the motor controller (MCU) 2 is reset or the brake signal is reset, the vehicle controller (VCU) 1 resets the enable flag of the hill-holding assist function and then exits the hill-holding assist function. Thereby, it can effectively avoid the false triggering of the hill-holding assist function under the conditions of emergency braking and dynamic shifting of the vehicle, which is safe and reliable.

[0046] S8: Motor controller (MCU) 2 exits the hill-holding auxiliary function; Figure 1 Before exiting the hill-holding assist function, the motor controller (MCU) 2 will first reset the hill-holding assist enable signal of the motor controller (MCU) 2.

[0047] S9: End; corresponding Figure 1 S9 in.

[0048] Figure 2 It is a logical structure block diagram of a hill-holding assist system for a new energy vehicle of the present invention, comprising a vehicle controller (VCU) 1 and a motor controller (MCU) 2, wherein the vehicle controller (VCU) 1 is connected to the motor controller (MCU) 2.

[0049] Combine the following Figure 1 and Figure 2 The working principle of the present invention is introduced as follows:

[0050] First, the vehicle controller (VCU) 1 determines whether the brake status signal of the vehicle is set. If the vehicle controller (VCU) 1 determines that the brake status signal of the vehicle is set, the vehicle controller (VCU) 1 will determine whether the vehicle is in a stopped state. If the vehicle controller (VCU) 1 determines that the vehicle is in a stopped state, the vehicle controller (VCU) 1 will set the enable flag of the hill-holding assist function as a necessary condition for the motor controller (MCU) 2 to enter the hill-holding assist function. Among them, when the vehicle controller (VCU) 1 determines that the speed of the motor is less than the first preset speed and the duration is not less than the first preset time, the vehicle controller (VCU) 1 determines that the vehicle is in a stopped state, otherwise, the vehicle controller (VCU) 1 determines that the vehicle is not in a stopped state. Among them, the first preset speed is 10 revolutions per minute, and the first preset time is 100 milliseconds.

[0051] When the vehicle controller (VCU) 1 sets the enable flag of the hill-holding assist function, the vehicle controller (VCU) 1 will send the enable signal of the hill-holding assist function to the motor controller (MCU) 2, and the motor controller (MCU) 2 receives the hill-holding assist enable signal of the vehicle controller (VCU) 1. After the motor controller (MCU) 2 receives the hill-holding assist enable signal sent by the vehicle controller (VCU) 1, the motor controller (MCU) 2 will determine whether the vehicle meets the first preset condition or the second preset condition. If the motor controller (MCU) 2 determines that the vehicle meets the first preset condition or the vehicle meets the second preset condition, the motor controller (MCU) 2 hill-holding assist function enable signal is set, and the motor controller (MCU) 2 enters the hill-holding assist function. Thereby, the vehicle enters the hill-holding assist function quickly. Among them, the first preset condition is that the gear position of the vehicle is the drive gear and the speed of the motor is less than the second preset speed; the second preset condition is that the gear position of the vehicle is the reverse gear and the speed of the motor is greater than the third preset speed. Among them, the second preset speed is -10rpm, and the third preset speed is 10rpm.

[0052] After the motor controller (MCU) 2 enters the hill-holding assist function, the motor controller (MCU) 2 will realize the hill-holding assist function by controlling the motor to zero speed. The hill-holding assist function is maintained for a second preset time each time, and the motor controller (MCU) 2 enters the hill-holding assist function three times in succession. The second preset time is 20 seconds. This can assist the driver to hold and start on a slope, and the effect of assisting the driver to hold and start on a slope is good and the cost is low.

[0053] After the motor controller (MCU) 2 enters the hill-holding assist function, the motor controller (MCU) 2 will determine whether the motor controller (MCU) 2 meets the conditions for exiting the hill-holding assist function. If it does, the motor controller (MCU) 2 exits the hill-holding assist function. And before exiting the hill-holding assist function, the motor controller (MCU) 2 will first reset the hill-holding assist enable signal of the motor controller (MCU) 2. Among them, the condition for the motor controller (MCU) 2 to exit the hill-holding assist function is that the vehicle controller (VCU) 1 resets the enable flag of the hill-holding assist function or the vehicle gear changes or the motor controller (MCU) 2 has entered the hill-holding assist function three times in a row. Among them, when the vehicle controller (VCU) 1 determines that the speed of the motor is greater than 200rpm or determines that the torque command of the vehicle controller (VCU) 1 is greater than the hill-holding assist value of the motor controller (MCU) 2 or determines that the hill-holding assist enable signal of the motor controller (MCU) 2 is reset or determines that the brake signal is reset, the vehicle controller (VCU) 1 resets the enable flag of the hill-holding assist function, and then exits the hill-holding assist function. Therefore, the false triggering of the hill-holding assist function can be effectively avoided under the working conditions of emergency braking and dynamic gear shifting of the vehicle, which is safe and reliable. In addition, the present invention can also improve the problems of failure, false triggering and long slope sliding distance of the vehicle's hill-holding assist function.

[0054] Functions and Effects of the Embodiments

[0055] When the vehicle controller (VCU) 1 sets the enable flag of the hill-holding assist function, the vehicle controller (VCU) 1 will send the enable signal of the hill-holding assist function to the motor controller (MCU) 2, and the motor controller (MCU) 2 receives the hill-holding assist enable signal of the vehicle controller (VCU) 1. After the motor controller (MCU) 2 receives the hill-holding assist enable signal sent by the vehicle controller (VCU) 1, the motor controller (MCU) 2 will determine whether the vehicle meets the first preset condition or the second preset condition. If the motor controller (MCU) 2 determines that the vehicle meets the first preset condition or the vehicle meets the second preset condition, the motor controller (MCU) 2 hill-holding assist function enable signal is set, and the motor controller (MCU) 2 enters the hill-holding assist function. Thereby, the vehicle enters the hill-holding assist function quickly. Among them, the first preset condition is that the gear position of the vehicle is the drive gear and the speed of the motor is less than the second preset speed; the second preset condition is that the gear position of the vehicle is the reverse gear and the speed of the motor is greater than the third preset speed. Among them, the second preset speed is -10rpm, and the third preset speed is 10rpm. After the motor controller (MCU) 2 enters the hill-holding assist function, the motor controller (MCU) 2 will realize the hill-holding assist function by controlling the motor to zero speed. The hill-holding assist function maintains the second preset time each time, and the motor controller (MCU) 2 enters the hill-holding assist function 3 times in succession. Among them, the second preset time is 20 seconds. Then it can assist the driver to hold and start on the slope, and the effect of assisting the driver to hold and start is good and the cost is low. After the motor controller (MCU) 2 enters the hill-holding assist function, the motor controller (MCU) 2 will determine whether the motor controller (MCU) 2 meets the conditions for exiting the hill-holding assist function. If it does, the motor controller (MCU) 2 exits the hill-holding assist function. And before exiting the hill-holding assist function, the motor controller (MCU) 2 will first reset the hill-holding assist enable signal of the motor controller (MCU) 2. Among them, the condition for the motor controller (MCU) 2 to exit the hill-holding assist function is that the vehicle controller (VCU) 1 resets the enable flag of the hill-holding assist function or the vehicle gear changes or the motor controller (MCU) 2 has entered the hill-holding assist function 3 times in succession. Among them, when the vehicle controller (VCU) 1 determines that the speed of the motor is greater than 200rpm, or determines that the torque command of the vehicle controller (VCU) 1 is greater than the hill-holding assist value of the motor controller (MCU) 2, or determines that the hill-holding assist enable signal of the motor controller (MCU) 2 is reset, or determines that the brake signal is reset, the vehicle controller (VCU) 1 resets the enable flag of the hill-holding assist function, and then exits the hill-holding assist function. Thereby, it is possible to effectively avoid the false triggering of the hill-holding assist function under the working conditions of emergency braking and dynamic shifting of the vehicle, which is safe and reliable. In addition, the present invention can also improve the problems of failure, false triggering, and long sliding distance of the vehicle's hill-holding assist function.

[0056] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A hill-holding assist method for a new energy vehicle, characterized in that: The method comprises the following steps: S1: The vehicle controller (VCU) determines whether the vehicle's brake status signal is set. If so, it enters S2, if not, it enters S9; S2: The vehicle control unit (VCU) determines whether the vehicle is in a stopped state. If so, it enters S3; if not, it enters S9; S3: The vehicle control unit (VCU) sets the enable flag of the hill-holding assist function; S4: The motor controller (MCU) receives the hill-holding assist enable signal from the vehicle control unit (VCU); S5: The motor controller (MCU) determines whether the vehicle meets the first preset condition or the second preset condition. If yes, the process proceeds to S6; if no, the process proceeds to S9; S6: The motor controller (MCU) enters the hill-holding assist function; S7: The motor controller (MCU) determines whether the motor controller (MCU) meets the conditions for exiting the hill-holding assist function. If so, the process proceeds to S8; if not, the process proceeds to S6; S8: The motor controller (MCU) exits the hill-holding assist function; S9: End.

2. A hill-holding assist method for a new energy vehicle as claimed in claim 1, characterized in that: In S2, when the vehicle controller (VCU) determines that the rotation speed of the motor is less than the first preset rotation speed and the duration is not less than the first preset time, the vehicle controller (VCU) determines that the vehicle is in a stopped state.

3. A hill-holding assist method for a new energy vehicle as claimed in claim 1, characterized in that: The first preset condition is that the gear position of the vehicle is the driving gear and the rotation speed of the motor is less than the second preset rotation speed.

4. A hill-holding assist method for a new energy vehicle as claimed in claim 1, characterized in that: The second preset condition is that the gear position of the vehicle is the reverse gear and the rotation speed of the motor is greater than the third preset rotation speed.

5. A hill-holding assist method for a new energy vehicle as claimed in claim 1, characterized in that: In S6, after the motor controller (MCU) enters the hill-holding assist function, the motor controller (MCU) implements the hill-holding assist function by controlling the motor to zero speed. The hill-holding assist function is maintained for a second preset time each time, and the motor controller (MCU) enters the hill-holding assist function three times in succession.

6. A hill-holding assist method for a new energy vehicle as claimed in claim 5, characterized in that: The condition for the motor controller (MCU) to exit the hill-holding assist function is that the vehicle controller (VCU) resets the enable flag of the hill-holding assist function or the vehicle gear position changes or the motor controller (MCU) has entered the hill-holding assist function three times in a row.

7. A hill-holding assist method for a new energy vehicle as claimed in claim 2, characterized in that: The first preset rotation speed is 10 revolutions per minute; the first preset time is 100 milliseconds.

8. A hill-holding assist method for a new energy vehicle as claimed in any one of claims 5 to 6, characterized in that: The second preset time is 20 seconds.

9. A hill-holding assist system for a new energy vehicle as claimed in any one of claims 1 to 8, characterized in that: It includes a vehicle control unit (VCU) and a motor control unit (MCU), and the vehicle control unit (VCU) is connected to the motor control unit (MCU).

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