Forklift ramp load control method

Abstract

This invention discloses a forklift ramp load control method, comprising the following steps: S1, obtaining the ramp inclination degree α; S2, if the ramp inclination degree α < n, execute S1; if n ≤ α ≤ m, execute S3; S3, obtaining the forklift's travel speed V, determining whether the forklift is in a ramp slippage state, and if so, executing S4; S4, braking the forklift through the braking system for a braking time t; S5, after the braking system finishes braking, detecting the forklift's braking status; if the forklift is not in a stopped state, execute S6; if the forklift is in a stopped state, execute S7; S6, braking the forklift through motor drive; S7, end. This application identifies whether the vehicle is traveling on a ramp by recognizing the road surface, and monitors the vehicle's speed when traveling on a ramp, thereby timely identifying whether the vehicle is slipping on the ramp, controlling the slippage risk, and eliminating the risk of the entire vehicle stalling and slipping on a ramp under full load climbing conditions.

Description

Technical Field

[0001] This invention relates to the field of forklift braking technology, specifically a forklift ramp load control method. Background Technology

[0002] Heavy-duty electric forklifts, due to their large weight, require particularly safe braking when fully loaded uphill, as this is a crucial guarantee for the safe operation of the entire vehicle. When fully loaded uphill, hydraulic system malfunctions, such as valve jamming or sudden pressure drops, as well as improper driver operation, can lead to serious risks of slipping and rolling backwards. Summary of the Invention

[0003] The purpose of this invention is to provide a forklift ramp load control method to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A forklift ramp load control method includes the following steps:

[0006] S1. When the forklift is climbing a slope under load, the slope inclination degree α is obtained by the forklift's posture.

[0007] S2. If the slope inclination α < n, then execute S1; if n ≤ α ≤ m, then execute S3.

[0008] S3. Obtain the forklift's travel speed V. Determine whether the forklift is in a slope state based on the forklift's travel speed V. If so, execute S4.

[0009] S4. Brake the forklift using the braking system for a braking time of t.

[0010] S5. After the braking system finishes braking, check the forklift braking status. If the forklift is not stopped, execute S6; if the forklift is stopped, execute S7.

[0011] S6. Braking of the forklift is achieved by driving the motor.

[0012] S7, End.

[0013] As a further aspect of the present invention: the forklift is equipped with an attitude sensor, which obtains the tilt angle of the forklift as a whole. The slope tilt degree α is obtained by the vehicle tilt angle. Based on the different tire deformation rates, road surface errors and bump rates, the system sets the α accuracy as follows: solid tire accuracy ±7.9%, pneumatic tire accuracy ±10.2%.

[0014] As a further aspect of the present invention: in S2, n = 2°; m = 14°.

[0015] As a further aspect of the present invention: in S3, the sloping state includes sloping in neutral, sloping in reverse, and sloping in forward gear.

[0016] As a further aspect of the present invention: the speed of the forklift when it is determined to be in a slope-running state is V. L And V L ≥2.8 km / h.

[0017] As a further aspect of the present invention: in S4, the braking system includes a service braking system and a parking braking system, wherein the service braking system and the parking braking system are combined to perform braking.

[0018] As a further aspect of the present invention: when the service braking system and the parking braking system are combined for braking, the braking ratio is:

[0019] When the α angle is between 2° and 6°: the service brake operates at 75% + the parking brake operates at 25% for continuous braking;

[0020] When the α angle is between 6° and 9°: the service brake operates at 55% + the parking brake operates at 45% for continuous braking;

[0021] When the α angle is between 9° and 12°: the service brake operates at 35% + the parking brake operates at 65% for continuous braking;

[0022] When the α angle is between 12° and 14°: the service brake operates at 15% and the parking brake operates at 85% for continuous braking.

[0023] As a further aspect of the present invention, the braking time in S4 is 0.9-1.4 seconds.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. This application identifies whether a vehicle is traveling on a slope by recognizing the road surface. When traveling on a slope, the vehicle speed is monitored, thereby timely identifying whether the vehicle is slipping on the slope. This allows for the control of potential slippage risks and eliminates the risk of the vehicle stalling and slipping on a slope under full load climbing conditions.

[0026] 2. This application is equipped with slope control. Therefore, when operating on a slope, for example, if the driver forgets to press the parking brake and takes his foot off the pedal, the loaded vehicle may go downhill. At this time, the active control will immediately take effect to achieve steady-state parking braking, thereby eliminating hidden risks such as misoperation.

[0027] 3. In active braking, this application sets the ratio combination of service brake and parking brake to ensure braking effect while ensuring steady-state control of braking as much as possible, thereby achieving smooth braking and improving driving comfort. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the control method logic of this application. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figure 1 In this embodiment of the invention, a forklift ramp load control method includes the following steps:

[0031] S1. When the forklift is climbing a slope under load, the slope inclination α is obtained through the forklift's posture. The forklift is equipped with a posture sensor, which obtains the overall tilt angle of the forklift. The slope inclination α is obtained by the tilt angle of the forklift. The system default algorithm for the slope inclination α accuracy is set according to different tire deformation rates, road surface errors, and bump rates. The system sets the α accuracy as follows: solid tire accuracy ±7.9%, pneumatic tire accuracy ±10.2%. In this embodiment, the tilt angle of the forklift is taken as the tilt angle of the slope where the forklift is located. The accuracy means that the system has a certain deviation fluctuation in the angle value to ensure that the system will not misjudge and thus produce an unstable control effect. The cumulative error of the vehicle body tilt angle is used to cover the slope error by the cumulative error of tire deformation rate, road surface error, and bump rate. The system can thus obtain a more accurate slope value, thereby improving the system control accuracy.

[0032] S2. If the slope inclination α < n, then execute S1; if n ≤ α ≤ m, then execute S3. In this embodiment, n = 2°; m = 14°.

[0033] S3. Obtain the forklift's travel speed V. The forklift's travel speed V is used to determine if it is in a rolling state. When rolling, the drive wheels rotate in the opposite direction, causing the drive axle to rotate in the opposite direction, which in turn causes the drive motor to rotate in the opposite direction. This trend is received by the motor and transmitted to the vehicle controller VCU to determine the rolling state. Rolling states include rolling in neutral, reverse, and forward gears. The forklift speed when it is determined to be in a rolling state is V. L And V L ≥2.8 km / h, if so, execute S4;

[0034] S4. Brake the forklift using the braking system for a braking time of t.

[0035] The braking system includes a service braking system and a parking braking system, which work together to apply brakes. The braking ratio during this combined braking operation is:

[0036] When the α angle is between 2° and 6°: the service brake operates at 75% and the parking brake operates at 25% for continuous braking, with a braking time of 0.9-1.4 seconds;

[0037] When the α angle is between 6° and 9°: the service brake operates at 55% and the parking brake operates at 45% for continuous braking, with a braking time of 0.9-1.4 seconds;

[0038] When the α angle is between 9° and 12°: the service brake operates at 35% and the parking brake operates at 65% for continuous braking, with a braking time of 0.9-1.4 seconds;

[0039] When the α angle is between 12° and 14°: Continuous braking with 15% service brake and 85% parking brake. Braking time is 0.9-1.4 seconds.

[0040] S5. After the braking system finishes braking, check the forklift braking status. If the forklift is not stopped, execute S6; if the forklift is stopped, execute S7.

[0041] S6. Braking of the forklift is achieved by driving the motor.

[0042] S7, End.

[0043] The above-mentioned ramp braking safety technology has been successfully applied to a 16-ton heavy-duty electric forklift.

[0044] The above-mentioned ramp braking safety technology has been successfully applied to a 16-ton heavy-duty electric forklift. When the forklift is fully loaded with 16 tons of goods, it slowly accelerates uphill in the initial stage, finally climbing the 13.5° ramp at a speed of 3.6 km / h. At this point, the driver releases neutral, the system automatically detects, and operates at a speed of 12°-14°. The service brake operates at 15% + the parking brake at 85% continuous braking, with a braking time of 1.1 seconds, maintaining stable and smooth control. When the machine is reversed, the driver presses the accelerator pedal, and the speed instantly reaches 3.5 km / h. At this point, the ramp is at 5°, and the system starts to work, with the service brake operating at 75% + the parking brake at 25% continuous braking, with a braking time of 0.9-1.4 seconds, keeping the speed within a reasonable range.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0046] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A forklift ramp load control method, characterized in that, Includes the following steps: S1. When the forklift is climbing a slope under load, the slope inclination degree α is obtained by the forklift's posture. S2. If the slope inclination α < n, then execute S1; if n ≤ α ≤ m, then execute S3; where n = 2°; m = 14°. S3. Obtain the forklift's travel speed V. Determine whether the forklift is in a slope state based on the forklift's travel speed V. If so, execute S4. S4. The forklift is braked by a braking system for a braking time of t. The braking system includes a service braking system and a parking braking system, which are combined for braking. The braking ratio is: When the α angle is between 2° and 6°: the service brake operates at 75% + the parking brake operates at 25% for continuous braking; When the α angle is between 6° and 9°: the service brake operates at 55% + the parking brake operates at 45% for continuous braking; When the α angle is between 9° and 12°: the service brake operates at 35% + the parking brake operates at 65% for continuous braking; When the α angle is between 12° and 14°: the service brake operates at 15% + the parking brake operates at 85% for continuous braking; The braking time is 0.9-1.4 seconds. S5. After the braking system finishes braking, check the forklift braking status. If the forklift is not stopped, execute S6; if the forklift is stopped, execute S7. S6. Braking of the forklift is achieved by driving the motor. S7, End.

2. The forklift ramp load control method according to claim 1, characterized in that, The forklift is equipped with an attitude sensor to obtain the overall tilt angle of the forklift. The slope tilt degree α is obtained by the vehicle tilt angle. Based on different tire deformation rates, road surface errors and bump rates, the system sets the α accuracy as follows: solid tire accuracy ±7.9% and pneumatic tire accuracy ±10.2%.

3. The forklift ramp load control method according to claim 1, characterized in that, In S3, the sliding state includes sliding in neutral, sliding in reverse, and sliding in forward gear.

4. A forklift ramp load control method according to claim 1 or 3, characterized in that, The forklift's speed when it is determined to be in a slippery state is V. L And V L ≥2.8 km / h.

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