An unmanned forklift angle correction system and control method

Abstract

The application discloses an angle correction system of an unmanned forklift, which comprises a steering motor and a steering controller in communication with the steering motor, wherein the steering controller is connected with an upper controller, an incremental steering encoder and an absolute value encoder are arranged on the steering motor, the incremental steering encoder is in signal communication with the steering controller, and the absolute value encoder is in signal communication with the steering controller or the upper controller, the application calculates the deviation value of the correct angle and the error angle through the external absolute value encoder and the VCU controller, compensates the angle issued by the upper controller, realizes closed-loop control of the steering angle, and reduces the angle calculation deviation caused by the cumulative error of the original steering encoder.

Description

Technical Field

[0001] This invention relates to the field of steering control technology for unmanned vehicles, specifically an angle correction system and control method for an unmanned forklift. Background Technology

[0002] The vehicle steering system is a series of devices used to change or maintain the direction of travel or reversing of a vehicle. In existing driverless forklifts, steering control is particularly important due to the complexity of the operating environment.

[0003] In the existing steering system control of unmanned forklifts, the steering encoder may lose pulse signals. Over time, this can cause angular deviations. Furthermore, the cumulative steering variation of the angle encoder is not eliminated, leading to increased steering errors after long-term use. Summary of the Invention

[0004] The purpose of this invention is to provide an angle correction system and control method for an unmanned forklift to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An angle correction system for an unmanned forklift includes a steering motor and a steering controller connected to the steering motor. The steering controller is connected to a host controller. An incremental steering encoder and an absolute encoder are connected to the steering motor. The incremental steering encoder is signal-connected to the steering controller, and the absolute encoder is signal-connected to the steering controller or the host controller.

[0007] As a further aspect of the present invention: the steering motor is provided with a zero-position switch, and the zero-position switch is connected to the steering controller signal.

[0008] As a further aspect of the present invention: a VCU controller is connected between the steering controller and the host controller, and the VCU controller is signal-connected to the steering controller and the host controller.

[0009] As a further aspect of the present invention: the absolute encoder is signal-connected to the VCU controller.

[0010] As a further aspect of the present invention: the incremental steering encoder is a magnetic induction incremental encoder, and the absolute encoder is connected to the output shaft of the steering motor through gear meshing.

[0011] As a further aspect of the present invention: the zero-position switch is installed on the steering wheel gear ring that is powered by the steering motor.

[0012] As a further aspect of the present invention: the steering controller, VCU controller, and host controller are also connected to a lithium battery pack and a key switch.

[0013] An angle correction control method for an unmanned forklift includes the following steps:

[0014] Step 1: Power on the system and mark the zero position of the steering system using the zero-position switch;

[0015] Step 2: When the vehicle is running, the VCU controller acquires the angle β of the incremental steering encoder and the angle α of the absolute encoder, and transmits the acquired angle parameters to the host controller. At the same time, it receives the steering target angle γ sent by the host controller based on the vehicle's running status.

[0016] Step 3: The VCU controller calculates the corrected target angle δ based on the parameters obtained in Step 2;

[0017] Step 4: The VCU controller sends the corrected target angle δ to the steering controller, which then controls the steering motor to turn to the target angle.

[0018] As a further aspect of the present invention: step 1 includes the following steps:

[0019] Step 1.1: Power on the system and obtain the status of the zero-position switch through the steering controller. If the zero-position switch is triggered, proceed to step 1.2; if the zero-position switch is not triggered, proceed to step 1.3.

[0020] Step 1.2: The zero-position switch is triggered, and the current position is recorded as the steering zero position. The steering controller transmits the zero-position signal to the VCU controller, and the VCU controller records the reading of the absolute encoder at this time as zero degrees.

[0021] Step 1.3: If the zero-position switch is not triggered, the steering controller controls the steering motor to turn at a constant speed in a fixed direction. When the zero-position switch is triggered, the current position is recorded as the steering zero position. If the zero-position switch is not triggered even after rotating to the limit position, the steering motor is controlled to turn at a constant speed in the opposite direction until the zero-position switch is triggered and recorded as the steering zero position. Then the steering controller transmits the zero-position signal to the VCU controller, and the VCU controller records the reading of the absolute encoder at this time as zero degrees.

[0022] As a further aspect of the present invention: the formula for calculating the corrected target angle δ in step 3 is: δ=γ+(α-β).

[0023] Compared with the prior art, the beneficial effects of the present invention are: the present invention calculates the deviation value between the correct angle and the error angle by using an external absolute encoder and VCU controller, and compensates for the angle sent down by the upper controller, thereby realizing closed-loop control of the steering angle, thereby reducing the angle calculation deviation caused by the cumulative error of the original steering encoder. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the circuit principle in this embodiment;

[0025] Figure 2 This is a schematic diagram of the control flow in this embodiment;

[0026] In the diagram: 1-Steering motor, 2-Steering controller, 3-Host controller, 4-Incremental steering encoder, 5-Absolute encoder, 6-Zero position switch, 7-VCU controller, 8-Lithium battery pack, 9-Key switch. Detailed Implementation

[0027] 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.

[0028] Please see Figure 1-2 In this embodiment of the invention, an unmanned forklift angle correction system includes a steering motor 1 and a steering controller 2 connected to the steering motor 1. The steering controller 2 is connected to a host controller 3, and a VCU controller 7 is connected between the steering controller 2 and the host controller 3. The VCU controller 7 is signal-connected to the steering controller 2 and the host controller 3. An incremental steering encoder 4 and an absolute encoder 5 are connected to the steering motor 1. The incremental steering encoder 4 is signal-connected to the steering controller 2, and the absolute encoder 5 is signal-connected to the steering controller 2 or the host controller 3. A zero-position switch 6 is provided on the steering motor 1, and the zero-position switch 6 is signal-connected to the steering controller 2. In this embodiment, the absolute encoder 5 is signal-connected to the VCU controller 7, the incremental steering encoder 4 is a magnetic induction incremental encoder, and the absolute encoder 5 is connected to the output shaft of the steering motor 1 through gear meshing. The zero-position switch 6 is installed on the steering wheel gear ring that is power-connected to the steering motor 1. The steering controller 2, the VCU controller 7, and the host controller 3 are also connected to a lithium battery pack 8 and a key switch 9.

[0029] An angle correction control method for an unmanned forklift includes the following steps:

[0030] Step 1: Power on the system and mark the zero position of the steering system using the zero-position switch;

[0031] Step 1 includes the following steps:

[0032] Step 1.1: Power on the system and obtain the status of the zero-position switch 6 through the steering controller 2. If the zero-position switch 6 is triggered, proceed to step 1.2; if the zero-position switch 6 is not triggered, proceed to step 1.3.

[0033] Step 1.2: Zero-position switch 6 is triggered, and the current position is recorded as the steering zero position. Steering controller 2 transmits the zero-position signal to VCU controller 7, and VCU controller 7 records the reading of the absolute encoder at this time as zero degrees.

[0034] Step 1.3: If the zero-position switch is not triggered, the steering controller 2 controls the steering motor 1 to turn at a constant speed in a fixed direction. When the zero-position switch is triggered, the current position is recorded as the steering zero position. If the zero-position switch is not triggered even after rotating to the limit position, the steering motor 1 is controlled to turn at a constant speed in the opposite direction until the zero-position switch is triggered and recorded as the steering zero position. Then the steering controller 2 transmits the zero-position signal to the VCU controller 7, and the VCU controller 7 records the reading of the absolute encoder at this time as zero degrees.

[0035] Step 2: When the vehicle is running, the VCU controller acquires the angle β of the incremental steering encoder 4 and the angle α of the absolute encoder 5, and transmits the acquired angle parameters to the host controller 3. At the same time, it receives the steering target angle γ sent by the host controller 3 according to the vehicle running status.

[0036] Step 3: The VCU controller calculates the corrected target angle δ based on the parameters obtained in Step 2. The formula for calculating the target angle δ is: δ=γ+(α-β)

[0037] Step 4: The VCU controller 7 sends the corrected target angle δ to the steering controller 2, and the steering controller 2 controls the steering motor 1 to turn to the target angle.

[0038] 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.

[0039] 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. An angle correction system for an unmanned forklift, comprising a steering motor (1) and a steering controller (2) connected to the steering motor (1), wherein the steering controller (2) is connected to a host controller (3), characterized in that, An incremental steering encoder (4) and an absolute encoder (5) are connected to the steering motor (1). The incremental steering encoder (4) is connected to the steering controller (2) by signal, and the absolute encoder (5) is connected to the steering controller (2) or the host controller (3) by signal. A VCU controller (7) is connected between the steering controller (2) and the host controller (3), and the VCU controller (7) is signal-connected to the steering controller (2) and the host controller (3); Its control method includes the following steps: Step 1: Power on the system and mark the zero position of the steering system using the zero-position switch; Step 2: When the vehicle is running, the VCU controller acquires the angle β of the incremental steering encoder (4) and the angle α of the absolute encoder (5), and transmits the acquired angle parameters to the host controller (3). At the same time, it receives the steering target angle γ issued by the host controller (3) based on the vehicle's running status. Step 3: The VCU controller (7) calculates the corrected target angle δ based on the parameters obtained in step 2; the formula for calculating the corrected target angle δ is: δ=γ+(α-β) Step 4: The VCU controller (7) sends the corrected target angle δ to the steering controller (2), and the steering controller (2) controls the steering motor (1) to turn to the target angle.

2. The unmanned forklift angle correction system according to claim 1, characterized in that, The steering motor (1) is equipped with a zero-position switch (6), which is connected to the steering controller (2) via a signal.

3. The unmanned forklift angle correction system according to claim 1, characterized in that, The absolute encoder (5) is signal-connected to the VCU controller (7).

4. The unmanned forklift angle correction system according to claim 1, characterized in that, The incremental steering encoder (4) is a magnetic induction incremental encoder, and the absolute encoder (5) is connected to the output shaft of the steering motor (1) through gear meshing.

5. The unmanned forklift angle correction system according to claim 2, characterized in that, The zero-position switch (6) is installed on the steering wheel gear ring that is powered by the steering motor (1).

6. The unmanned forklift angle correction system according to claim 1, characterized in that, The steering controller (2), VCU controller (7), and host controller (3) are also connected to a lithium battery pack (8) and a key switch (9).

7. The unmanned forklift angle correction system according to claim 1, characterized in that, Step 1 includes the following steps: Step 1.1: Power on the system and obtain the status of the zero-position switch (6) through the steering controller (2). If the zero-position switch (6) is triggered, proceed to step 1.

2. If the zero-position switch (6) is not triggered, proceed to step 1.

3. Step 1.2: The zero-position switch (6) is triggered, and the current position is recorded as the steering zero position. The steering controller (2) transmits the zero-position signal to the VCU controller (7), and the VCU controller (7) records the reading of the absolute encoder at this time as zero degrees. Step 1.3: If the zero-position switch is not triggered, the steering controller (2) controls the steering motor (1) to turn at a constant speed in a fixed direction. When the zero-position switch is triggered, the current position is recorded as the steering zero position. If the zero-position switch is not triggered even when rotated to the limit position, the steering motor (1) is controlled to turn at a constant speed in the opposite direction until the zero-position switch is triggered and recorded as the steering zero position. Then the steering controller (2) transmits the zero-position signal to the VCU controller (7). The VCU controller (7) records the reading of the absolute encoder at this time as zero degrees.

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