Steering control method for high-position picking vehicle

Abstract

The invention discloses a steering control method for a high-position picking vehicle. The steering control method comprises the following steps that S1, the lifting height H1 of a pallet fork is obtained; s2, the mass G1 of the lifting component is obtained; s3, the gravity center height H of the picking vehicle is calculated according to the lifting height H1 of the pallet fork and the mass G1 of the lifting component; s4, the gravity center height range of the picking vehicle is set to be Hmin-Hmax; in the gravity center height range, the larger the gravity center height H, calculated in the step S3, of the picking vehicle is, the smaller the steering angle is, and the lower the vehicle running speed during steering is, and the gravity center height of the fork picking vehicle is calculated according to the fork height of the fork picking vehicle and the mass of the lifting part; and then the steering range and the steering speed of the picking vehicle are controlled according to the gravity center height of the picking vehicle, so that the steering safety of the picking vehicle can be controlled, and the steering risk is reduced.

Description

Technical Field

[0001] The invention relates to the field of steering systems for order picking vehicles, and in particular to a steering control method for a high-position order picking vehicle. Background Art

[0002] A high-level picking vehicle is an industrial vehicle in which the driver and the operating console are lifted together with the forks. Since the driver and the operating console are lifted together with the forks, the steering safety requirements of the high-level picking vehicle are higher. The steering angle and driving speed of the existing high-level picking vehicles are only related to the lifting height of the forks, and are not related to the height direction of the center of gravity of the vehicle. The steering safety control is not optimal, and there are safety risks. Summary of the invention

[0003] The object of the present invention is to provide a steering control method for a high-position picking vehicle to solve the problems raised in the above-mentioned background technology.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A steering control method for a high-position order picking vehicle comprises the following steps:

[0006] S1, obtain the fork lifting height H1;

[0007] S2, obtaining the mass G1 of the lifting component;

[0008] S3, calculating the center of gravity height H of the picking vehicle according to the lifting height H1 of the fork and the mass G1 of the lifting component;

[0009] S4. Set the center of gravity height range of the picking vehicle to H min -H max ; Within the center of gravity height range, the larger the center of gravity height H of the picking vehicle calculated in S3, the smaller the steering angle and the lower the vehicle speed when turning.

[0010] As a further solution of the present invention: the fork lifting height H1 in S1 is obtained by obtaining the fork lifting signal C1 through the fork lifting height sensor, and the fork lifting height H1=Hmax*C1 / 5 is calculated according to the fork lifting signal C1;

[0011] in:

[0012] H1: Fork lifting height, mm;

[0013] Hmax: Maximum lifting height of the fork, mm, which can be set according to the maximum lifting height of the picking vehicle;

[0014] C1: voltage signal, 0-5V, 5V corresponds to the maximum lifting height Hmax.

[0015] As a further solution of the present invention: the lifting components in S2 include an operating platform, a driver, a gantry moving component, a fork and a load.

[0016] As a further solution of the present invention: in said S2, by detecting the bottom pressure signal C2 of the lifting cylinder, the mass of the lifting component G1=K1*P*A*K2 / g is calculated;

[0017] in:

[0018] G1: Mass of lifting components (operating console, driver, gantry moving parts, fork and load), kg;

[0019] K1: Weight coefficient of lifting components. Since the lifting cylinder drives the lifting components to lift through the fixed pulley and lifting chain, the weight of the lifting components is equal to half of the force of the lifting cylinder, K1 = 0.5;

[0020] P: lifting cylinder bottom pressure, P = (C2 / 5) * Pmax, MPa;

[0021] C2: voltage signal, 0-5V, 5V corresponds to the maximum pressure Pmax of the hydraulic system;

[0022] Pmax: Maximum pressure of the hydraulic system, MPa, which can be set according to the maximum pressure of the hydraulic system of the picking vehicle;

[0023] A: Effective working area of ​​lifting cylinder, cm 2 ;

[0024] K2: unit conversion coefficient, K2=100;

[0025] g: acceleration due to gravity, m / s 2 , take g=9.8.

[0026] As a further solution of the present invention: in S3, the height of the center of gravity of the picking vehicle H = (H1*G1+H2*G2) / (G1+G2);

[0027] in:

[0028] H: Height of the center of gravity of the picking vehicle (including lifting components), mm;

[0029] H2: Height of the center of gravity of the picking vehicle (excluding lifting components), mm, set according to the specific vehicle model;

[0030] G2: Mass of the picking vehicle (excluding lifting components), kg, set according to the specific vehicle model.

[0031] As a further solution of the present invention: S4 comprises the following steps:

[0032] S4.1. Set the threshold H of the center height of the picking vehicle阈值1 , H 阈值2 , H 阈值3 , H 阈值4 , and H min <H 阈值1 <H 阈值2 <H 阈值3 <H 阈值4 <H max ;

[0033] S4.2, comparing the height H of the center of gravity of the picking vehicle obtained in S3 with the set threshold;

[0034] S4.3, when 0≤H<H 阈值1 When H 阈值1 ≤H<H 阈值2 When H 阈值2 ≤H<H 阈值3 When H 阈值3 ≤H<H 阈值4 When H>H 阈值4 When , execute S4.8;

[0035] S4.4, the controller controls the steering wheel angle θ to a range of ±90°;

[0036] S4.5, the controller controls the steering wheel angle θ to a range of ±15°;

[0037] S4.6, the controller controls the steering wheel angle θ to a range of ±10°;

[0038] S4.7, the controller controls the steering wheel angle θ to a range of ±5°;

[0039] S4.8, the controller controls the steering wheel angle range to: 0°, the steering function is locked;

[0040] θ: Steering wheel angle.

[0041] As a further solution of the present invention: in S4.4:

[0042] When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K3*(C3 / 5)*nmax;

[0043] When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K4*(C3 / 5)*nmax;

[0044] When -15°<θ≤-10° or 10°≤θ<15°, the controller controls the traction motor speed n 牵引=K5*(C3 / 5)*nmax;

[0045] When -90°≤θ≤-15° or 15°≤θ≤90°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax;

[0046] in:

[0047] n 牵引 : traction motor speed, r / min;

[0048] K3, K4, K5, K6: driving speed adjustment coefficient, take K3 = 1, K4 = 0.8, K5 = 0.5, K6 = 0.2;

[0049] C3: Vehicle driving accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax when the vehicle is at the maximum driving speed;

[0050] nmax: traction motor speed at the vehicle's maximum speed, r / min.

[0051] As a further solution of the present invention: in S4.5:

[0052] When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K4*(C3 / 5)*nmax;

[0053] When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K5*(C3 / 5)*nmax;

[0054] When -15°<θ≤-10° or 10°≤θ<15°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax

[0055] in:

[0056] n 牵引 : traction motor speed, r / min;

[0057] K4, K5, K6: driving speed adjustment coefficient, take K4 = 0.8, K5 = 0.5, K6 = 0.2;

[0058] C3: Vehicle driving accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax when the vehicle is at the maximum driving speed;

[0059] nmax: traction motor speed at the vehicle's maximum speed, r / min.

[0060] As a further solution of the present invention: in S4.6:

[0061] When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K5*(C3 / 5)*nmax;

[0062] When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax

[0063] in:

[0064] n 牵引 : traction motor speed, r / min;

[0065] K5, K6: driving speed adjustment coefficient, take K5 = 0.5, K6 = 0.2;

[0066] C3: Vehicle driving accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax when the vehicle is at the maximum driving speed;

[0067] nmax: traction motor speed at the vehicle's maximum speed, r / min.

[0068] As a further solution of the present invention: in S4.7:

[0069] The controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax;

[0070] in:

[0071] n 牵引 : traction motor speed, r / min;

[0072] K6: driving speed adjustment coefficient, take K6 = 0.2;

[0073] C3: vehicle accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax at the maximum vehicle speed; nmax: traction motor speed at the maximum vehicle speed, r / min.

[0074] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention calculates the height of the center of gravity of the fork picking truck by the height of the forks of the fork picking truck and the mass of the lifting part, and then controls the turning range of the picking truck and the vehicle's driving speed during turning according to the height of the center of gravity of the picking truck, thereby controlling the safety of the picking truck's turning and reducing the risk of steering. DETAILED DESCRIPTION

[0075] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0076] In an embodiment of the present invention, a steering control method for a high-position picking vehicle includes a controller, a fork lifting height sensor, a lifting component (operating console, driver, gantry moving component, fork and load) weighing sensor, a vehicle driving accelerator, etc. The fork lifting height sensor is used to detect the fork lifting height, and its variation range is 0-5V; the lifting component (operating console, driver, gantry moving component, fork and load) weighing sensor adopts a pressure sensor, which is used to detect the bottom pressure C2 of the lifting cylinder, and its variation range is 0-5V. The controller calculates the weight of the lifting component according to the bottom pressure signal of the lifting cylinder; the vehicle driving accelerator signal C3 is used to detect the driver's driving intention, and its variation range is 0-5V; the controller calculates the center of gravity height of the whole vehicle (including the lifting component) according to the lifting height and the weight of the lifting components (operating console, driver, gantry moving component, fork and load), the weight of the whole vehicle (excluding the lifting component), and the center of gravity height of the whole vehicle (excluding the lifting component). The controller controls the speed of the traction motor according to the driving acceleration signal, thereby controlling the driving speed of the vehicle.

[0077] The following steps are involved:

[0078] S1, obtain the fork lifting height H1, and calculate the fork lifting height H1 = Hmax*C1 / 5 according to the fork lifting signal C1;

[0079] in:

[0080] H1: Fork lifting height, mm;

[0081] Hmax: Maximum lifting height of the fork, mm, which can be set according to the maximum lifting height of the picking vehicle;

[0082] C1: voltage signal, 0-5V, 5V corresponds to the maximum lifting height Hmax;

[0083] S2, obtain the mass G1 of the lifting component; detect the bottom pressure signal C2 of the lifting cylinder, and calculate the mass G1 of the lifting component = K1*P*A*K2 / g;

[0084] in:

[0085] G1: Mass of lifting components (operating console, driver, gantry moving parts, fork and load), kg;

[0086] K1: Weight coefficient of lifting components. Since the lifting cylinder drives the lifting components to lift through the fixed pulley and lifting chain, the weight of the lifting components is equal to half of the force of the lifting cylinder, K1 = 0.5;

[0087] P: lifting cylinder bottom pressure, P = (C2 / 5) * Pmax, MPa;

[0088] C2: voltage signal, 0-5V, 5V corresponds to the maximum pressure Pmax of the hydraulic system;

[0089] Pmax: Maximum pressure of the hydraulic system, MPa, which can be set according to the maximum pressure of the hydraulic system of the picking vehicle;

[0090] A: Effective working area of ​​lifting cylinder, cm 2 ;

[0091] K2: unit conversion coefficient, K2=100;

[0092] g: acceleration due to gravity, m / s 2 , take g = 9.8;

[0093] S3. Calculate the height H of the center of gravity of the picking vehicle according to the lifting height H1 of the fork and the mass G1 of the lifting component. The height H of the center of gravity of the picking vehicle = (H1*G1+H2*G2) / (G1+G2);

[0094] in:

[0095] H: Height of the center of gravity of the picking vehicle (including lifting components), mm;

[0096] H2: Height of the center of gravity of the picking vehicle (excluding lifting components), mm, set according to the specific vehicle model;

[0097] G2: The mass of the picking vehicle (excluding lifting components), kg, set according to the specific vehicle model

[0098] S4. Set the center of gravity height range of the picking vehicle to H min -H max ; Within the range of the center of gravity height, the greater the center of gravity height H of the picking vehicle calculated in S3, the smaller the steering angle and the smaller the steering speed;

[0099] S4 includes the following steps:

[0100] S4.1. Set the threshold H of the center height of the picking vehicle 阈值1 , H 阈值2 , H 阈值3 , H 阈值4 , and H min <H 阈值1 <H 阈值2 <H 阈值3 <H 阈值4 <Hmax ;H 阈值1 , H 阈值2 , H 阈值3 , H 阈值4 , can be set according to the specific vehicle model. For 1.4t high-level picking truck, select H 阈值1 =900mm, H 阈值2 =1800mm, H 阈值3 =2700mm, H 阈值4 =3600mm;

[0101] S4.2, comparing the height H of the center of gravity of the picking vehicle obtained in S3 with the set threshold;

[0102] S4.3, when 0≤H<H 阈值1 When H 阈值1 ≤H<H 阈值2 When H 阈值2 ≤H<H 阈值3 When H 阈值3 ≤H<H 阈值4 When H>H 阈值4 When , execute S4.8;

[0103] S4.4, the controller controls the steering wheel angle θ to a range of ±90°;

[0104] When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K3*(C3 / 5)*nmax;

[0105] When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K4*(C3 / 5)*nmax;

[0106] When -15°<θ≤-10° or 10°≤θ<15°, the controller controls the traction motor speed n 牵引 =K5*(C3 / 5)*nmax;

[0107] When -90°≤θ≤-15° or 15°≤θ≤90°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax

[0108] S4.5, the controller controls the steering wheel angle θ to a range of ±15°;

[0109] When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K4*(C3 / 5)*nmax;

[0110] When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K5*(C3 / 5)*nmax;

[0111] When -15°<θ≤-10° or 10°≤θ<15°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax;

[0112] S4.6, the controller controls the steering wheel angle θ to a range of ±10°;

[0113] When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K5*(C3 / 5)*nmax;

[0114] When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax;

[0115] S4.7, the controller controls the steering wheel angle θ within the range of: ±5°; the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax;

[0116] S4.8, the controller controls the steering wheel angle range to: 0°, the steering function is locked;

[0117] θ: steering wheel angle;

[0118] n 牵引 : traction motor speed, r / min;

[0119] K3, K4, K5, K6: driving speed adjustment coefficient, take K3 = 1, K4 = 0.8, K5 = 0.5, K6 = 0.2;

[0120] C3: Vehicle driving accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax when the vehicle is at the maximum driving speed;

[0121] nmax: traction motor speed at the vehicle's maximum speed, r / min.

[0122] 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 present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0123] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A steering control method for a high-position picking vehicle, characterized in that: The following steps are involved: S1, obtain the fork lifting height H1; S2, obtaining the mass G1 of the lifting component; S3, calculating the center of gravity height H of the picking vehicle according to the lifting height H1 of the fork and the mass G1 of the lifting component; S4. Set the center of gravity height range of the picking vehicle to H min -H max ; Within the center of gravity height range, the larger the center of gravity height H of the picking vehicle calculated in S3, the smaller the steering angle and the lower the vehicle speed when turning.

2. A steering control method for a high-position picking vehicle according to claim 1, characterized in that: In S1, the fork lifting height H1 is obtained by obtaining the fork lifting signal C1 through the fork lifting height sensor, and the fork lifting height H1=Hmax*C1 / 5 is calculated according to the fork lifting signal C1; in: H1: Fork lifting height, mm; Hmax: Maximum lifting height of the fork, mm, which can be set according to the maximum lifting height of the picking vehicle; C1: voltage signal, 0-5V, 5V corresponds to the maximum lifting height Hmax.

3. A steering control method for a high-position picking vehicle according to claim 1, characterized in that: The lifting components in S2 include an operating platform, a driver, a gantry moving component, a fork and a load.

4. A steering control method for a high-position picking vehicle according to claim 1, characterized in that: In the step S2, the lifting cylinder bottom pressure signal C2 is detected to calculate the lifting component mass G1=K1*P*A*K2 / g; in: G1: Mass of lifting components (operating console, driver, gantry moving parts, fork and load), kg; K1: Weight coefficient of lifting components. Since the lifting cylinder drives the lifting components to lift through the fixed pulley and lifting chain, the weight of the lifting components is equal to half of the force of the lifting cylinder, K1 = 0.5; P: lifting cylinder bottom pressure, P = (C2 / 5) * Pmax, MPa; C2: voltage signal, 0-5V, 5V corresponds to the maximum pressure Pmax of the hydraulic system; Pmax: Maximum pressure of the hydraulic system, MPa, which can be set according to the maximum pressure of the hydraulic system of the picking vehicle; A: Effective working area of ​​lifting cylinder, cm 2 ; K2: unit conversion coefficient, K2=100; g: acceleration due to gravity, m / s 2 , take g=9.

8.

5. The steering control method of a high-position picking vehicle according to claim 1, characterized in that: In S3, the height of the center of gravity of the picking vehicle H = (H1*G1+H2*G2) / (G1+G2); in: H: Height of the center of gravity of the picking vehicle (including lifting components), mm; H2: Height of the center of gravity of the picking vehicle (excluding lifting components), mm, set according to the specific vehicle model; G2: Mass of the picking vehicle (excluding lifting components), kg, set according to the specific vehicle model.

6. A steering control method for a high-position order picking vehicle according to claim 1, characterized in that: The S4 comprises the following steps: S4.

1. Set the threshold H of the center of gravity height of the picking vehicle 阈值1 , H 阈值2 , H 阈值3 , H 阈值4 , and H min <H 阈值1 <H 阈值2 <H 阈值3 <H 阈值4 <H max ; S4.2, comparing the height H of the center of gravity of the picking vehicle obtained in S3 with the set threshold; S4.3, when 0≤H<H 阈值1 When H 阈值1 ≤H<H 阈值2 When H 阈值2 ≤H<H 阈值3 When H 阈值3 ≤H<H 阈值4 When H>H 阈值4 When , execute S4.8; S4.4, the controller controls the steering wheel angle θ to a range of ±90°; S4.5, the controller controls the steering wheel angle θ to a range of ±15°; S4.6, the controller controls the steering wheel angle θ to a range of ±10°; S4.7, the controller controls the steering wheel angle θ to a range of ±5°; S4.8, the controller controls the steering wheel angle range to: 0°, the steering function is locked; θ: Steering wheel angle.

7. A steering control method for a high-position picking vehicle according to claim 6, characterized in that: In S4.4: When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K3*(C3 / 5)*nmax; When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K4*(C3 / 5)*nmax; When -15°<θ≤-10° or 10°≤θ<15°, the controller controls the traction motor speed n 牵引 =K5*(C3 / 5)*nmax; When -90°≤θ≤-15° or 15°≤θ≤90°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax; in: n 牵引 : traction motor speed, r / min; K3, K4, K5, K6: driving speed adjustment coefficient, take K3 = 1, K4 = 0.8, K5 = 0.5, K6 = 0.2; C3: Vehicle driving accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax when the vehicle is at the maximum driving speed; nmax: traction motor speed at the vehicle's maximum speed, r / min.

8. The steering control method of a high-position picking vehicle according to claim 6, characterized in that: In S4.5: When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K4*(C3 / 5)*nmax; When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K5*(C3 / 5)*nmax; When -15°<θ≤-10° or 10°≤θ<15°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax; in: n 牵引 : traction motor speed, r / min; K4, K5, K6: driving speed adjustment coefficient, take K4 = 0.8, K5 = 0.5, K6 = 0.2; C3: Vehicle driving accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax when the vehicle is at the maximum driving speed; nmax: traction motor speed at the vehicle's maximum speed, r / min.

9. A steering control method for a high-position picking vehicle according to claim 6, characterized in that: In S4.6: When -5°<θ<5°, the controller controls the traction motor speed n 牵引 =K5*(C3 / 5)*nmax; When -10°<θ≤-5° or 5°≤θ<10°, the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax; in: n 牵引 : traction motor speed, r / min; K5, K6: driving speed adjustment coefficient, take K5 = 0.5, K6 = 0.2; C3: vehicle accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax at the maximum vehicle speed; nmax: traction motor speed at the maximum vehicle speed, r / min.

10. The steering control method of a high-position order picking vehicle according to claim 1, characterized in that: In S4.7: the controller controls the traction motor speed n 牵引 =K6*(C3 / 5)*nmax; in: n 牵引 : traction motor speed, r / min; K6: driving speed adjustment coefficient, take K6 = 0.2; C3: vehicle accelerator signal, 0-5V, 5V corresponds to the traction motor speed nmax at the maximum vehicle speed; nmax: traction motor speed at the maximum vehicle speed, r / min.