Brake control system and method

Abstract

The invention relates to the technical field of forklift braking, and particularly discloses a braking control system and method.The system comprises an execution module, an induction module, an electric braking module, a hydraulic braking module and a control module; the controller is configured to execute segmented cooperative braking according to the rotation angle of the brake pedal; when the rotation angle of the brake pedal is in a first brake interval, only the electric brake module is started for regenerative braking; and when the rotation angle of the brake pedal is in the second brake interval, the electric brake module is controlled to output the maximum regenerative braking force, and meanwhile, the hydraulic brake module is started to conduct composite braking, so that the emergency braking strength and the response speed are ensured. The comprehensive beneficial effects of recovering braking energy, greatly reducing the loss of friction plates, reducing the impact of a transmission system and shortening the braking distance are achieved, and the economical efficiency, the safety and the reliability of the forklift are improved.

Description

Technical Field

[0001] This invention relates to the technical field of forklift braking, and specifically to a braking control system and method. Background Technology

[0002] As a common industrial handling vehicle, the braking performance of forklifts is directly related to operational safety. Currently, traditional forklift braking systems typically use a pure hydraulic braking scheme. When the driver presses the brake pedal, the master cylinder is pushed through a mechanical linkage or hydraulic booster mechanism, which transmits the brake oil pressure to the brake slave cylinders at the wheels, driving the brake pads to rub against the brake discs (or brake drums), thereby generating braking torque to slow down the vehicle.

[0003] However, this traditional pure friction braking method has the following obvious drawbacks:

[0004] 1. Long braking distance and slow response: Pure hydraulic braking systems require time to build up pressure. In emergency braking conditions, the braking response is delayed, resulting in a long braking distance and posing a safety hazard.

[0005] 2. Large impact, damage to the transmission system: The huge inertial impact force generated during braking will directly act on the drive motor shaft and transmission system. Over time, this can easily lead to fatigue or even breakage of the motor shaft, affecting the life of the equipment.

[0006] 3. Friction pads wear out quickly and maintenance costs are high: The braking process relies entirely on the wear of friction pads to consume kinetic energy. Friction pads become vulnerable parts and require frequent inspection and replacement, which increases maintenance and operating costs.

[0007] 4. Energy waste: The kinetic energy of the vehicle during braking is completely dissipated as heat energy through friction and cannot be recovered and utilized, resulting in low energy efficiency. Summary of the Invention

[0008] This invention addresses the aforementioned problems and aims to provide a braking control system and method that solves the problems of long braking distance, large impact, easy damage to components, and energy waste in traditional braking schemes.

[0009] To achieve the above objectives, the present invention provides a braking control system applied to a forklift, wherein the forklift has drive wheels at its bottom, and the braking control system includes:

[0010] The execution module includes the brake pedal;

[0011] The sensing module includes an angle sensor disposed at the brake pedal, the angle sensor being used to detect the rotation angle of the brake pedal;

[0012] An electric braking module includes a drive motor that is connected to the drive wheel, the drive motor having a motor operating state and a generator operating state;

[0013] The hydraulic braking module is used to apply friction braking force to the drive wheels;

[0014] The control module includes a controller, which is communicatively connected to the angle sensor, the drive motor, and the hydraulic braking module.

[0015] The controller is configured to:

[0016] Based on the brake pedal rotation angle detected by the angle sensor, determine the corresponding braking range:

[0017] When the rotation angle of the brake pedal is in the first braking range, the drive motor is controlled to switch to generator operation to generate regenerative braking force, and the hydraulic braking module is kept in a non-working state.

[0018] When the rotation angle of the brake pedal is in the second braking range, the drive motor is controlled to output a preset maximum regenerative braking force, and the hydraulic braking system is activated simultaneously for coordinated braking.

[0019] According to the above-described braking control system, when the rotation angle of the brake pedal is between 0° and 20°, the brake pedal is in the first braking range; when the rotation angle of the brake pedal is between 20° and 30°, the brake pedal is in the second braking range.

[0020] According to the above-described braking control system, when the rotation angle of the brake pedal is 0°, the drive motor is in a non-working state or in a motor running state.

[0021] According to the above-described braking control system, the controller is further configured to: control the amplitude of the regenerative braking current generated by the drive motor to be positively correlated with the rotation angle of the brake pedal, and the regenerative braking current charges the battery through an inverter circuit.

[0022] According to the above-described braking control system, the hydraulic braking module includes a brake pump, a left brake assembly, and a right brake assembly. The left brake assembly is located on the left side of the drive wheel, and the right brake assembly is located on the right side of the drive wheel. The brake pump is electrically connected to the controller and is used to simultaneously supply oil to the left brake assembly and the right brake assembly.

[0023] According to the above-described braking control system, the hydraulic braking module further includes a brake fluid reservoir, the outlet of which is connected to the inlet of the brake fluid pump, and the outlet of the brake fluid pump is connected to both the left brake assembly and the right brake assembly via a T-connector.

[0024] According to the above-described braking control system, the execution module further includes a return spring, which is arranged on one side of the brake pedal and can drive the brake pedal to remain at a position with a rotation angle of 0°.

[0025] According to the above-described braking control system, the control module further includes a battery located on one side of the controller and used to power the controller.

[0026] A braking control method, applied to the braking control system described above, includes the following steps:

[0027] The controller obtains the rotation angle of the brake pedal through an angle sensor;

[0028] The controller determines the braking range to which the rotation angle of the brake pedal belongs;

[0029] If the rotation angle is within the braking range of 0°-20°, the controller triggers the regenerative braking mode. The controller sends a command to the drive motor to switch it to generator mode, generate regenerative braking force, and keep the hydraulic braking system disconnected.

[0030] If the rotation angle is within the braking range of 20°-30°, the controller triggers the compound braking mode. The controller controls the drive motor to output the preset maximum regenerative braking force and simultaneously starts the hydraulic braking system for compound braking.

[0031] According to the forklift braking control method described above, when the rotation angle of the brake pedal is 0°, the controller controls the drive motor to be in a non-working state or a motor running state.

[0032] The present invention has the following beneficial effects:

[0033] 1. By using the rotation angle of the brake pedal to divide the braking range, the electric brake can be used alone or in combination with the hydraulic brake, which can save energy and ensure braking efficiency during emergency braking.

[0034] 2. When emergency braking is required, the operator will often press the brake pedal further, which will increase the rotation angle of the brake pedal. At this time, the combined braking of electric braking and hydraulic braking, especially the rapid response of the compound braking mode during emergency braking, significantly shortens the braking distance and greatly improves the safety of forklift operation.

[0035] 3. The regenerative braking process is smooth and prioritizes the consumption of vehicle kinetic energy, effectively reducing the impact of direct mechanical braking on the motor shaft and transmission system, and extending the service life of key components;

[0036] 4. In most conventional deceleration scenarios, contactless regenerative braking is used first, which greatly reduces the frequency of use and wear rate of the hydraulic braking module, extends the replacement cycle of the hydraulic braking module, and reduces maintenance costs.

[0037] 5. The kinetic energy during braking is converted into electrical energy and stored back in the battery, which improves energy utilization and extends the continuous working time of the forklift after a single charge, meeting the requirements of energy conservation and environmental protection. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the braking control system of an embodiment.

[0039] In the picture:

[0040] 100. Execution module; 110. Brake pedal; 120. Return spring;

[0041] 200. Sensing module; 210. Angle sensor;

[0042] 300. Electric braking module; 310. Drive motor;

[0043] 400. Hydraulic brake module; 410. Brake pump; 420. Left brake assembly; 430. Right brake assembly; 440. Brake fluid reservoir; 450. T-connector;

[0044] 500. Control module; 510. Controller; 520. Battery;

[0045] 600. Drive wheel. Detailed Implementation

[0046] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical solution of the present invention. However, the invention is not limited to these embodiments.

[0047] like Figure 1 As shown, a braking control system includes an execution module 100, a sensing module 200, an electric braking module 300, a hydraulic braking module 400, and a control module 500.

[0048] In this embodiment, the braking control system is applied to a forklift. A drive wheel 600 is provided at the bottom of the forklift. The braking control system is used to brake the drive wheel 600. The braking method can be selected as either electric braking module 300 braking alone or electric braking module 300 and hydraulic braking module 400 braking in coordination. Electric braking module 300 is used in the slow braking stage, in which the hydraulic braking module 400 is not needed, which can reduce the wear of the hydraulic braking module 400 itself and reduce the energy consumption of the hydraulic braking module 400 starting. When the electric module and hydraulic braking module 400 brake in coordination, the braking efficiency can be greatly improved and the braking distance can be shortened. When applied in the emergency braking stage, it can reduce wear and tear while ensuring braking efficiency.

[0049] The execution module 100 includes a brake pedal 110 and a spring. A return spring 120 is arranged on one side of the brake pedal 110 and can drive the brake pedal 110 to remain in a position with a rotation angle of 0°. The return spring 120 ensures that the brake pedal 110 can return to the 0° position accurately and stably when the driver does not press the brake pedal 110, preventing the brake pedal 110 from rotating arbitrarily. At the same time, the return spring 120 can provide a preload force for the brake pedal 110, so that when the driver presses the brake pedal 110, he can control the rotation angle of the brake pedal 110 by controlling the magnitude of the force.

[0050] It is known that the driver controls the force applied to the brake pedal 110 based on the urgency of braking, which determines the rotation angle of the brake pedal 110. When the distance to the obstacle or the position to be stopped is still relatively far, the driver can gently press the brake pedal 110, resulting in a smaller rotation angle. When the distance to the obstacle or the position to be stopped is very close, the driver will press the brake pedal 110 harder, resulting in a larger rotation angle. Therefore, in this embodiment, when the rotation angle of the brake pedal 110 is small, only the electric braking module 300 can be used. When the rotation angle of the brake pedal 110 is large, a combination of electric braking module 300 and hydraulic braking module 400 is used for braking, which conforms to the driver's normal operating habits and improves safety performance.

[0051] The sensing module 200 includes an angle sensor 210 disposed at the brake pedal 110. The angle sensor 210 is used to detect the rotation angle of the brake pedal 110. In this embodiment, the brake pedal 110 is rotatably disposed in the cab of the forklift via a rotating shaft. The rotation angle of the brake pedal 110 is consistent with the rotation angle of the rotating shaft. The angle sensor 210 is arranged at the rotating shaft. The rotation angle of the brake pedal 110 is detected by detecting the rotation angle of the rotating shaft.

[0052] The electric braking module 300 includes a drive motor 310 that is connected to the drive wheel 600. The drive motor 310 has a motor operating state and a generator operating state. When the drive motor 310 is in the motor operating state, it converts electrical energy into kinetic energy, which drives the drive wheel 600 to rotate, thereby realizing the forward or backward movement of the forklift. When the drive motor 310 is in the generator operating state, the kinetic and potential energy of the forklift is transferred to the drive motor 310 through the drive wheel 600, converting mechanical energy into electrical energy and returning it to the battery. For electric forklifts, the recovered energy can be directly used for driving, extending the working time after a single charge, improving work efficiency, reducing energy consumption, reducing operating costs, and meeting the requirements of green environmental protection. Of course, both states of the drive motor 310 are its working states. The drive motor 310 should also have a non-working state, in which the forklift does not perform the corresponding actions.

[0053] The control module 500 includes a controller 510 and a battery 520. The battery 520 is located on one side of the controller 510 and is used to provide power to the controller 510. The controller 510 is communicatively connected to the angle sensor 210, the drive motor 310, and the hydraulic braking module 400. In this embodiment, the hydraulic braking module 400 is used to apply friction braking force to the drive wheel 600. The controller 510 can receive the rotation angle signal of the brake pedal 110 detected by the angle sensor 210 and can control the drive motor 310 and the hydraulic braking module 400 to perform corresponding actions.

[0054] Therefore, in this embodiment, the controller 510 is configured to determine the braking range to which the brake pedal 110 belongs based on the rotation angle detected by the angle sensor 210. When the rotation angle of the brake pedal 110 is in the first braking range, the controller controls the drive motor 310 to switch to generator operation to generate regenerative braking force and maintains the hydraulic braking module 400 in a non-working state. When the rotation angle of the brake pedal 110 is in the second braking range, the controller controls the drive motor 310 to output a preset maximum regenerative braking force and simultaneously activates the hydraulic braking system for coordinated braking. The rotation angle in the second braking range is greater than the rotation angle in the first braking range, which can separate the driver's braking intention from the optimal braking energy. The braking strategy is integrated with the driver's braking intention, which can be fed back through the brake pedal 110. When the rotation angle of the brake pedal 110 is in the first braking range, it corresponds to normal deceleration and anticipatory braking. During this stage, the kinetic energy of the forklift is completely recovered into electrical energy by the drive motor 310. This not only maximizes energy recovery, but also completely avoids brake pad wear because the hydraulic brake is not working. When the rotation angle of the brake pedal 110 is in the second braking range, it corresponds to emergency and strong braking. When greater braking force is required, the system first allows the regenerative braking to output its current maximum value, and then immediately activates the hydraulic brake to provide the remaining required braking force. This ensures that sufficient and rapid braking effect can be provided under any circumstances.

[0055] In this embodiment, by fully allocating the normal deceleration scenario (first braking zone) to regenerative braking, it is ensured that braking energy can be efficiently recovered in most daily operations. As long as braking demand is within the first zone, the brake pads experience zero wear. For forklifts that frequently start and stop, this can extend the life of the brake pads by several times or even dozens of times. Furthermore, in emergency braking situations, the combined mode of "electric braking + hydraulic braking" provides a more powerful and reliable braking force limit than single hydraulic braking, especially under heavy loads and downhill conditions, ensuring double safety.

[0056] Furthermore, to achieve energy recovery from the drive motor 310, the drive motor 310 is equipped with an inverter. The inverter converts kinetic energy into electrical energy. Therefore, the controller 510 is further configured to: control the amplitude of the regenerative braking current generated by the drive motor 310 to be positively correlated with the rotation angle of the brake pedal 110. The regenerative braking current charges the battery through the inverter circuit. The "positive correlation" between the regenerative braking current and the rotation angle of the brake pedal 110 means that the deeper the driver presses the pedal, the greater the braking force, and the greater the braking force, and the less force is applied when releasing the pedal. This is completely consistent with the physical intuition and muscle memory of controlling hydraulic braking force by pressing the brake pedal depth when driving a traditional vehicle. Meanwhile, the battery can recover energy in real time and in a matching manner according to the actual braking force required. The power of energy recovery changes synchronously with the braking demand to avoid waste. Since the regenerative braking force and the rotation angle of the brake pedal 110 change continuously and linearly, when the angle of the brake pedal 110 reaches the critical point of the first braking range, the regenerative braking force will smoothly reach its maximum value under the current working condition. When it is necessary to enter the second braking range, the hydraulic brake intervenes on the basis that the regenerative braking force has stabilized at a high level. The two are superimposed smoothly without impact, avoiding vehicle nodding or cargo shaking caused by sudden changes in braking force, thus improving driving comfort and cargo stability.

[0057] The preset maximum regenerative braking force refers to the braking force generated by the drive motor 310 at its rated maximum power.

[0058] Specifically, when the rotation angle of the brake pedal 110 is between 0° and 20°, the brake pedal 110 is in the first braking range. When the rotation angle of the brake pedal 110 is between 20° and 30°, the brake pedal 110 is in the second braking range. Of course, the first braking range does not include 0°. When the rotation angle of the brake pedal 110 is 0°, the drive motor 310 is in a non-working state or a motor running state. When the rotation angle of the brake pedal 110 is 0°, it means that the brake pedal 110 has not been pressed. At this time, the forklift is either in a stopped working state or in a normal driving state. Therefore, the drive motor 310 is in a non-working state or a motor running state.

[0059] The hydraulic braking module 400 includes a brake pump 410, a left brake assembly 420, a right brake assembly 430, and a brake fluid reservoir 440. The left brake assembly 420 is located on the left side of the drive wheel 600, and the right brake assembly 430 is located on the right side of the drive wheel 600. Both the left and right brake assemblies 420 are equipped with brake pads, and they operate synchronously, allowing for simultaneous friction braking from both sides to improve braking performance. The brake pump 410 is electrically connected to the controller 510 and is used to simultaneously brake the left brake assembly 420. The brake fluid reservoir 440 supplies oil to the right brake assembly 430. The outlet of the brake fluid reservoir 440 is connected to the inlet of the brake pump 410. The outlet of the brake pump 410 is connected to both the left brake assembly 420 and the right brake assembly 430 via a three-way connector 450. The controller 510 issues a brake control command to the brake pump 410 to start it. The brake pump 410 draws hydraulic oil from the brake fluid reservoir 440 and outputs it to the left brake assembly 420 and the right brake assembly 430, controlling them to brake synchronously.

[0060] In this embodiment, a braking control method is applied to the braking control system described above, and includes the following steps:

[0061] When the driver presses the brake pedal, the controller 510 obtains the rotation angle of the brake pedal 110 through the angle sensor 210.

[0062] The controller 510 determines the braking range to which the rotation angle of the brake pedal 110 belongs. If the brake pedal 110 is lightly pressed, the brake pedal 110 will be in the first braking range. If the brake pedal 110 is pressed hard, the brake pedal 110 will be in the second braking range.

[0063] If the rotation angle is within the braking range of 0°-20°, the controller 510 triggers the regenerative braking mode. The controller 510 sends a command to the drive motor 310 to switch it to generator mode, generate regenerative braking force, and keep the hydraulic braking system disconnected. During this process, the drive motor 310 generates braking force to perform slow braking. Its generator mode can convert the kinetic energy of the drive wheel 600 into electrical energy and store it in the battery, thus realizing energy recovery.

[0064] If the rotation angle is within the braking range of 20°-30°, the controller 510 triggers the compound braking mode. The controller 510 controls the drive motor 310 to output the preset maximum regenerative braking force and simultaneously starts the hydraulic braking system for compound braking. At this time, the drive motor 310 and the hydraulic braking system brake simultaneously, which can improve braking efficiency and shorten braking distance.

[0065] Of course, there is also a time when the rotation angle is 0°. When the rotation angle of the brake pedal 110 is 0°, the controller 510 controls the drive motor 310 to be in a non-working state or in a motor running state.

[0066] The technical solution of the present invention has been described in detail above with reference to the accompanying drawings. The described embodiments are used to help understand the concept of the present invention. The specific embodiments described herein are merely illustrative examples of the spirit of the present invention. Those skilled in the art to which this invention pertains can make various modifications or additions to the described specific embodiments or use similar methods to replace them, but without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

[0067] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0068] Furthermore, in this invention, descriptions involving terms such as "first," "second," and "a" are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0069] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0070] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

Claims

1. A braking control system applied to a forklift, wherein the forklift has drive wheels at its bottom, characterized in that, The braking control system includes: The execution module includes the brake pedal; The sensing module includes an angle sensor disposed at the brake pedal, the angle sensor being used to detect the rotation angle of the brake pedal; An electric braking module includes a drive motor that is connected to the drive wheel, the drive motor having a motor operating state and a generator operating state; The hydraulic braking module is used to apply friction braking force to the drive wheels; The control module includes a controller, which is communicatively connected to the angle sensor, the drive motor, and the hydraulic braking module. The controller is configured to: Based on the brake pedal rotation angle detected by the angle sensor, determine the corresponding braking range: When the rotation angle of the brake pedal is in the first braking range, the drive motor is controlled to switch to generator operation to generate regenerative braking force, and the hydraulic braking module is kept in a non-working state. When the rotation angle of the brake pedal is in the second braking range, the drive motor is controlled to output a preset maximum regenerative braking force, and the hydraulic braking system is activated simultaneously for coordinated braking.

2. The braking control system according to claim 1, characterized in that, When the rotation angle of the brake pedal is between 0° and 20°, the brake pedal is in the first braking range; when the rotation angle of the brake pedal is between 20° and 30°, the brake pedal is in the second braking range.

3. A braking control system according to claim 2, characterized in that, When the rotation angle of the brake pedal is 0°, the drive motor is in a non-working state or in a running state.

4. A braking control system according to claim 1, characterized in that, The controller is further configured to control the amplitude of the regenerative braking current generated by the drive motor to be positively correlated with the rotation angle of the brake pedal, and the regenerative braking current charges the battery through the inverter circuit.

5. A braking control system according to claim 1, characterized in that, The hydraulic braking module includes a brake pump, a left brake assembly, and a right brake assembly. The left brake assembly is located on the left side of the drive wheel, and the right brake assembly is located on the right side of the drive wheel. The brake pump is electrically connected to the controller and is used to supply oil to both the left and right brake assemblies simultaneously.

6. A braking control system according to claim 5, characterized in that, The hydraulic braking module also includes a brake fluid reservoir, the outlet of which is connected to the inlet of the brake fluid pump, and the outlet of the brake fluid pump is connected to both the left brake assembly and the right brake assembly via a T-connector.

7. A braking control system according to claim 1, characterized in that, The execution module also includes a return spring, which is arranged on one side of the brake pedal and can drive the brake pedal to remain in a position with a rotation angle of 0°.

8. A braking control system according to claim 1, characterized in that, The control module also includes a battery located on one side of the controller and used to power the controller.

9. A braking control method, applied to the braking control system as described in any one of claims 1-8, characterized in that, Including the following steps: The controller obtains the rotation angle of the brake pedal through an angle sensor; The controller determines the braking range to which the rotation angle of the brake pedal belongs; If the rotation angle is within the braking range of 0°-20°, the controller triggers the regenerative braking mode. The controller sends a command to the drive motor to switch it to generator mode, generate regenerative braking force, and keep the hydraulic braking system disconnected. If the rotation angle is within the braking range of 20°-30°, the controller triggers the compound braking mode. The controller controls the drive motor to output the preset maximum regenerative braking force and simultaneously starts the hydraulic braking system for compound braking.

10. A braking control method according to claim 9, characterized in that, When the rotation angle of the brake pedal is 0°, the controller controls the drive motor to be in a non-working state or in a motor running state.

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