Electric vehicle speed control methods

Abstract

This invention discloses a method for slowing down an electric vehicle, comprising: determining whether the activation conditions for a slowing down control mode are met; if so, activating the slowing down control mode; in the slowing down control mode, adjusting the set speed using a speed adjustment button on the vehicle control panel; based on the difference between the current speed and the set speed, the motor control system controls the motor to enter a speed control mode, or exit the speed control mode and enter a torque control mode, so that the vehicle travels at a speed not exceeding the set speed; in the speed control mode, the motor outputs braking torque; in the torque control mode, the motor stops outputting braking torque; determining whether the exit conditions for the slowing down control mode are met; if so, exiting the slowing down control mode. This method for slowing down an electric vehicle can achieve a slowing down function by controlling the motor through the motor control system when the electric vehicle is fully charged and descending a long distance for an extended period, ensuring stable driving at a constant speed.

Description

Technical Field

[0001] This invention relates to the field of vehicle retardation control technology, and more particularly to a method for retardation control of electric vehicles. Background Technology

[0002] For vehicles driving in mountainous areas, a suitable retarder can ensure that the vehicle maintains a stable speed during long downhill stretches. A retarder can reduce or eliminate the load on the service brakes, preventing overheating caused by prolonged use and potential emergency braking failure. Common retarding devices for gasoline-powered vehicles include engine retarders (engine exhaust brakes, compression brake lights), hydraulic retarders, and electric turbine retarders. However, electric vehicles currently do not have dedicated retarding devices.

[0003] Therefore, there is an urgent need for a method to slow down electric vehicles. Summary of the Invention

[0004] The purpose of this invention is to provide a method for slowing down an electric vehicle, in order to solve the problems in the prior art, and enable the electric vehicle to control the motor to output braking power through the control system to achieve a slowing function.

[0005] This invention provides a method for controlling the deceleration of an electric vehicle, comprising:

[0006] Determine if the activation conditions for the slow control mode are met; if so, activate the slow control mode.

[0007] In slow speed control mode, the set vehicle speed can be adjusted using the vehicle speed adjustment button, which is located on the vehicle control panel;

[0008] Based on the current vehicle speed and the set vehicle speed, the motor control system controls the motor to enter speed control mode or exit speed control mode and enter torque control mode, so that the vehicle travels at a speed not exceeding the set vehicle speed. In speed control mode, the motor outputs braking torque to decelerate the vehicle to the set vehicle speed; in torque control mode, the motor stops outputting braking torque.

[0009] Determine if the exit conditions for slow control mode are met. If they are met, exit slow control mode.

[0010] In the electric vehicle deceleration control method described above, preferably, the deceleration control mode activation condition includes simultaneously satisfying the following conditions:

[0011] The slow speed control mode signal is enabled.

[0012] The vehicle gear position is D, and the throttle is 0.

[0013] There is no current fault in the motor control system.

[0014] In the electric vehicle deceleration control method described above, preferably, the determination of whether the deceleration control mode activation condition is met specifically includes:

[0015] When the driver issues a command to activate the deceleration control mode, the motor control system determines whether the conditions for activating the deceleration control mode are met.

[0016] In the electric vehicle deceleration control method described above, preferably, the driver's deceleration control mode activation command is triggered by pressing a deceleration control mode switch, wherein the deceleration control mode switch is located on the vehicle control panel.

[0017] In the electric vehicle slow-down control method described above, preferably, when the activation conditions are met, a slow-down control mode indicator light for indicating the slow-down control mode is activated at the same time as the slow-down control mode is activated, wherein the slow-down control mode indicator light is disposed on the instrument panel.

[0018] If the activation conditions are not met, the slow control mode will not be activated, and the corresponding slow control mode indicator light will also not be activated.

[0019] The electric vehicle speed control method described above, preferably, includes adjusting the set vehicle speed via a speed adjustment button, specifically comprising:

[0020] Initialize the vehicle speed. If the current vehicle speed is less than or equal to the set vehicle speed threshold, the initial set vehicle speed will default to the current vehicle speed. If the current vehicle speed is greater than the set vehicle speed threshold, the initial set vehicle speed will default to the set vehicle speed threshold.

[0021] The vehicle speed can be adjusted using the speed adjustment button, wherein the adjustment range of the set speed is 10-80 km / h.

[0022] The electric vehicle speed control method described above, preferably, involves the motor control system controlling the motor to enter a speed control mode or exit a speed control mode and enter a torque control mode based on the magnitude of the current vehicle speed and the set vehicle speed, so that the vehicle travels at a speed not exceeding the set vehicle speed. Specifically, this includes:

[0023] If the current vehicle speed v > the set vehicle speed v0, the motor control system controls the motor to enter the speed control mode, and the motor outputs braking torque to decelerate the vehicle to the set speed.

[0024] If the current vehicle speed v ≤ the set vehicle speed v0-2, the motor control system controls the motor to exit the speed control mode and enter the torque control mode, and the motor stops outputting braking torque.

[0025] If the set vehicle speed v0-2 < current vehicle speed v ≤ set vehicle speed v0, then the motor control system and the motor will remain unchanged from the previous moment.

[0026] In the electric vehicle deceleration control method described above, preferably, the deceleration control mode exit condition includes satisfying any of the following conditions:

[0027] The slow control mode signal is off.

[0028] The vehicle gear position signal is not set to D;

[0029] The motor control system reports a current fault.

[0030] In the electric vehicle deceleration control method described above, preferably, in the deceleration control mode, the vehicle normally responds to the service braking signal, and in the deceleration control mode, energy recovery is not performed.

[0031] In the electric vehicle retardation control method described above, preferably, in the retardation control mode, if the current vehicle speed is less than the set vehicle speed, the motor control system responds to the torque command issued by the vehicle controller; if the current vehicle speed is greater than or equal to the set vehicle speed, the motor control system does not respond to the torque command issued by the vehicle controller.

[0032] This invention provides a method for slowing down an electric vehicle. The motor control system controls the motor to enter a speed control mode or exit the speed control mode and enter a torque control mode, so that the vehicle travels at a speed not exceeding the set speed. When the electric vehicle is fully charged and going downhill for a long time, the motor control system controls the motor to achieve the slowing function and ensure that the vehicle travels stably at a constant speed. Attached Figure Description

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0034] Figure 1 A flowchart illustrating an embodiment of the electric vehicle slow-down control method provided by the present invention;

[0035] Figure 2 A logic diagram of an embodiment of the electric vehicle speed control method provided by the present invention. Detailed Implementation

[0036] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0037] The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Terms such as “including” or “contains” mean that the element preceding the term encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as “above” and “below” are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0038] In this disclosure, when a specific component is described as being located between a first component and a second component, an intermediary component may or may not be present between the specific component and the first or second component. When a specific component is described as connecting to other components, the specific component may be directly connected to the other components without having an intermediary component, or it may not be directly connected to the other components but may have an intermediary component.

[0039] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0040] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0041] For electric vehicles, engine retarding devices (engine exhaust brake, compression brake light) are not suitable. Hydraulic retarders and eddy current retarders require development and matching, which is costly and complex to control, and is currently not used in electric vehicles. Therefore, matching hydraulic retarders and eddy current retarders to electric vehicles has the following disadvantages: it requires the development of physical interfaces in the power system, which is difficult; the development and procurement costs are high, increasing vehicle costs; it requires the installation of retarders, control harnesses, cooling systems, and other accessories, occupying space in the vehicle layout; the retarder control needs to be coordinated with the overall vehicle power system control, increasing the control difficulty and complexity; and it increases vehicle weight, which is not conducive to improving the driving range of new energy vehicles.

[0042] Cruise control allows the driver to maintain a constant speed at a specified pace without needing to operate the accelerator. However, this system has drawbacks. Cruise control has a minimum speed requirement, typically above 40 km / h. Furthermore, the cruise control system increases traction below the specified speed but provides no braking force above it. Therefore, cruise control is unsuitable for prolonged downhill driving and cannot provide deceleration control.

[0043] When a vehicle descends a long slope over an extended period, using the service brake to control speed can cause the braking system to overheat, leading to brake failure. For electric vehicles, when the battery is fully charged, energy recovery is typically not possible to avoid overcharging, thus preventing the increase in braking force. This invention addresses this issue by controlling the motor through a motor control system to achieve a slowing function during extended downhill descents when the electric vehicle is fully charged, ensuring stable vehicle operation at a constant speed.

[0044] like Figure 1 and Figure 2 As shown, the electric vehicle speed control method provided in this embodiment includes the following steps in actual execution:

[0045] Step S1: Determine whether the activation conditions for the slow control mode are met. If they are met, activate the slow control mode.

[0046] The activation conditions for the slow control mode include simultaneously satisfying the following conditions:

[0047] a) The slow speed control mode signal is enabled;

[0048] b) The vehicle gear position signal is D, and the throttle is 0;

[0049] c) The motor control system has no current faults.

[0050] Specifically, in response to the driver's command to activate the deceleration control mode, the motor control system determines whether the activation conditions for the deceleration control mode are met. The driver's command to activate the deceleration control mode is triggered by pressing a deceleration control mode switch, which is located on the vehicle's control panel.

[0051] Furthermore, in some embodiments of the present invention, when the activation conditions are met, the slow control mode indicator light for indicating the slow control mode is activated at the same time as the slow control mode is activated, wherein the slow control mode indicator light is disposed on the instrument panel; when the activation conditions are not met, the slow control mode is not activated, and the corresponding slow control mode indicator light is also not activated.

[0052] When the driver activates the deceleration control mode, the motor control system judges according to the activation logic. If the activation conditions are not met, the deceleration control mode is not activated, and the instrument panel indicates that the activation conditions are not met. If the activation conditions are met, the deceleration control mode is activated, and the relevant instrument panel indicator lights are activated.

[0053] Step S2: In slow speed control mode, adjust the set vehicle speed using the vehicle speed adjustment button, wherein the vehicle speed adjustment button is located on the vehicle control panel.

[0054] The adjustable range of the set vehicle speed is 10-80 km / h. It should be noted that the present invention does not specifically limit the adjustable range of the preset vehicle speed.

[0055] In one embodiment of the electric vehicle slow-down control method of the present invention, step S2 may specifically include:

[0056] Step S21: Initialize the set vehicle speed. If the current vehicle speed is less than or equal to the set vehicle speed threshold, the initial set vehicle speed is the current vehicle speed by default. If the current vehicle speed is greater than the set vehicle speed threshold, the initial set vehicle speed is the set vehicle speed threshold by default.

[0057] Step S22: Adjust the set speed using the speed adjustment button.

[0058] After the driver successfully activates the slow control mode, the vehicle will travel at a speed not exceeding the set value. The initial setting value after activation is the current vehicle speed (maximum 80km / h). The driver can adjust the setting value through the speed adjustment button, with an adjustment range of 10-80km / h.

[0059] Step S3: Based on the current vehicle speed and the set vehicle speed, the motor control system controls the motor to enter the speed control mode or exit the speed control mode and enter the torque control mode, so that the vehicle travels at a speed not exceeding the set vehicle speed. In the speed control mode, the motor outputs braking torque to decelerate the vehicle to the set vehicle speed; in the torque control mode, the motor stops outputting braking torque.

[0060] The torque control mode is the normal operating mode of the vehicle motor. In one embodiment of the electric vehicle retardation control method of the present invention, step S3 may specifically include:

[0061] Step S31: If the current vehicle speed v > the set vehicle speed v0, the motor control system controls the motor to enter the speed control mode and the motor outputs braking torque to decelerate the vehicle to the set speed.

[0062] Step S32: If the current vehicle speed v ≤ the set vehicle speed v0-2, the motor control system controls the motor to exit the speed control mode and enter the torque control mode, and the motor stops outputting braking torque.

[0063] Step S33: If the set vehicle speed v0-2 < current vehicle speed v ≤ set vehicle speed v0, then the motor control system and the motor will maintain the state of the previous moment.

[0064] Furthermore, in slow control mode, it responds normally to the service brake signal.

[0065] Furthermore, in slow-speed control mode, energy recovery is not performed. This prevents the electric vehicle's battery from overcharging when it is fully charged.

[0066] Furthermore, in slow control mode, if the current vehicle speed is less than the set vehicle speed, the motor control system responds to the torque command issued by the vehicle controller; if the current vehicle speed is greater than or equal to the set vehicle speed, the motor control system does not respond to the torque command issued by the vehicle controller.

[0067] Step S4: Determine whether the exit conditions for slow control mode are met. If they are met, exit slow control mode.

[0068] The exit condition for the slow control mode includes satisfying any of the following conditions:

[0069] a) The slow control mode signal is off;

[0070] b) The vehicle gear position signal is not in D gear;

[0071] c) The motor control system reports the current fault.

[0072] The electric vehicle speed control method provided in this embodiment of the invention, in speed control mode,

[0073] Based on the current vehicle speed and the set vehicle speed, the motor control system controls the motor to enter speed control mode or exit speed control mode and enter torque control mode, so that the vehicle travels at a speed not exceeding the set speed. When the electric vehicle is fully charged and going downhill for a long time, the motor control system controls the motor to achieve a slowing function, ensuring that the vehicle travels stably at a constant speed.

[0074] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0075] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A method for slowing down an electric vehicle, characterized in that, include: Determine if the activation conditions for the slow control mode are met; if so, activate the slow control mode. In slow speed control mode, the set vehicle speed is adjusted by the vehicle speed adjustment button, which is located on the vehicle control panel. In slow speed control mode, if the current vehicle speed is greater than or equal to the set vehicle speed, the motor control system will not respond to the torque command issued by the vehicle controller. Based on the current vehicle speed and the set vehicle speed, the motor control system controls the motor to enter speed control mode or exit speed control mode and enter torque control mode, so that the vehicle travels at a speed not exceeding the set vehicle speed. In speed control mode, the motor outputs braking torque to decelerate the vehicle to the set vehicle speed; in torque control mode, the motor stops outputting braking torque. Determine if the exit conditions for slow control mode are met. If they are met, exit slow control mode. The motor control system controls the motor to enter speed control mode or exit speed control mode and enter torque control mode based on the magnitude of the current vehicle speed and the set vehicle speed, so that the vehicle travels at a speed not exceeding the set vehicle speed. Specifically, this includes: If the current vehicle speed v > the set vehicle speed v0, the motor control system controls the motor to enter the speed control mode, and the motor outputs braking torque to decelerate the vehicle to the set speed. If the current vehicle speed v ≤ the set vehicle speed v0-2, the motor control system controls the motor to exit the speed control mode and enter the torque control mode, and the motor stops outputting braking torque. If the set vehicle speed v0-2 < current vehicle speed v ≤ set vehicle speed v0, then the motor control system and the motor will remain unchanged from the previous moment. The process of adjusting the set vehicle speed via the speed adjustment button specifically includes: Initialize the vehicle speed. If the current vehicle speed is less than or equal to the set vehicle speed threshold, the initial set vehicle speed will default to the current vehicle speed. If the current vehicle speed is greater than the set vehicle speed threshold, the initial set vehicle speed will default to the set vehicle speed threshold. The vehicle speed can be adjusted using the speed adjustment button, wherein the adjustment range of the set speed is 10-80 km / h.

2. The electric vehicle speed control method according to claim 1, characterized in that, The activation conditions for the slow control mode include the simultaneous fulfillment of the following conditions: The slow speed control mode signal is enabled. The vehicle gear position is D, and the throttle is 0. There is no current fault in the motor control system.

3. The electric vehicle speed control method according to claim 2, characterized in that, The determination of whether the slow control mode activation condition is met specifically includes: When the driver issues a command to activate the deceleration control mode, the motor control system determines whether the conditions for activating the deceleration control mode are met.

4. The electric vehicle speed control method according to claim 3, characterized in that, The driver's command to activate the deceleration control mode is triggered by pressing the deceleration control mode switch, which is located on the vehicle control panel.

5. The electric vehicle speed control method according to claim 1, characterized in that, When the activation conditions are met, the slow control mode indicator light for indicating the slow control mode is activated at the same time as the slow control mode is activated, wherein the slow control mode indicator light is set on the instrument panel. If the activation conditions are not met, the slow control mode will not be activated, and the corresponding slow control mode indicator light will also not be activated.

6. The electric vehicle slow-down control method according to claim 1, characterized in that, The exit condition for the slow control mode includes meeting any of the following conditions: The slow control mode signal is off. The vehicle gear position signal is not set to D; The motor control system reports a current fault.

7. The electric vehicle speed control method according to claim 1, characterized in that, In slow control mode, the vehicle responds normally to the service braking signal, and energy recovery is not performed in slow control mode.

8. The electric vehicle speed control method according to claim 1, characterized in that, In slow control mode, if the current vehicle speed is less than the set vehicle speed, the motor control system responds to the torque command issued by the vehicle controller.

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