Intelligent sensing following type transport vehicle and following method thereof

Abstract

The invention relates to the technical field of intelligent following, in particular to an intelligent sensing following type transport vehicle and a following method thereof. The transport vehicle is mainly composed of a loading frame, a pair of tires, a suspension assembly, a power assembly, a fulcrum adjusting assembly, an angle adjusting assembly, a tension sensor and an IMU. The tension sensor is arranged on a manual grabbing part of the loading frame to obtain tension in the horizontal direction and the vertical direction; the pair of tires is connected to the bottom of the loading frame through the suspension assembly, and the power assembly independently drives the two tires to rotate. The IMU is arranged on the suspension assembly to obtain the inclination angle, and the angle adjusting assembly drives the suspension assembly to rotate around the fulcrum rotating shaft through stretching and retracting to adjust the angle. According to the invention, each tire is provided with an independent suspension, so that when the trolley passes through a complex pothole field terrain, the shaking of the trolley body is reduced, the stability is improved, the energy consumption for keeping the balance of manpower is reduced, and the labor-saving effect is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent following, in particular to an intelligent following transport vehicle and a following method thereof. BACKGROUND

[0002] The "intelligent following trolley" is an intelligent mobile robot capable of following a target (such as a person, an object or a leading vehicle), which is widely used in logistics, security, transportation, agriculture and industrial automation and other fields. The "manpower following trolley" (i.e. a transport device that is guided by a person to walk and intelligently followed by the trolley) is a special form of the "intelligent following trolley". This type of trolley can better operate in complex terrain scenes to better assist humans in field work. For example, in the scenes of power maintenance and agricultural work.

[0003] The existing manpower trolley has poor off-road capability of the walking part during field operation. When running in the field terrain with many pits and bumps, it cannot well filter out the bumps, resulting in poor stability of the trolley body and difficulty in maintaining balance, and consuming more physical strength in controlling the vehicle. SUMMARY

[0004] In view of the above technical problems, the technical solution adopted by the present application is as follows: According to one aspect of the present application, an intelligent following transport vehicle is provided, comprising: a loading frame, a pair of tires, a suspension assembly, a power assembly, a fulcrum adjusting assembly, an angle adjusting assembly, a tension sensor and an IMU; The tension sensor is arranged at the manpower gripping part of the loading frame, and is used to obtain the horizontal tension and the vertical tension of the transport vehicle; The pair of tires are respectively connected to the bottom of the loading frame through the suspension assembly; the power assembly is connected with the tires, and is used to independently drive the two tires to rotate, respectively; The IMU is arranged on the suspension assembly, and is used to obtain the inclination angle of the suspension assembly; The fulcrum adjusting assembly comprises a sliding rail assembly, a screw rod driving assembly and a fulcrum shaft; The sliding rail assembly and the screw rod driving assembly are both fixedly arranged at the bottom of the loading frame, and the sliding direction of the sliding rail assembly and the driving direction of the screw rod driving assembly are both the same as the front-rear axial direction of the loading frame; the fulcrum shaft is rotatably arranged through the sliding part of the sliding rail assembly and the near-trolley end of the suspension assembly, so that the suspension assembly is rotatably connected with the loading frame; the fulcrum shaft is connected with the moving part of the screw rod driving assembly, and the screw rod driving assembly is used to drive the fulcrum shaft to move along the front-rear axial direction of the loading frame; The angle adjusting assembly is connected at both ends to the near-tire end of the suspension assembly and the bottom of the loading frame, respectively; the angle adjusting assembly drives the suspension assembly to rotate around the fulcrum shaft through the extension and contraction movement of the angle adjusting assembly, so as to adjust the angle of the suspension assembly.

[0005] Further, the angle adjusting assembly comprises an electric push rod or a hydraulic rod.

[0006] Further, the tension sensor is a strain gauge type force sensor.

[0007] Further, the suspension assembly comprises a load-bearing girder and two sub-suspension assemblies. The two sub-suspension assemblies are symmetrically arranged at two ends of the load-bearing girder, and each sub-suspension assembly is connected with one tire; the top of the load-bearing girder is rotationally connected with the fulcrum shaft. The sub-suspension assembly comprises two shock absorbers, a transmission rod, a wheel angle adjusting rod and a steering knuckle. The steering knuckle is connected with the tire on the outer side, and the two shock absorbers, the transmission rod and the wheel angle adjusting rod are connected between the load-bearing girder and the steering knuckle at two ends, respectively. The transmission rod is used to limit the transverse distance between the steering knuckle and the load-bearing girder. The wheel angle adjusting rod adjusts the inclination angle of the steering knuckle by its own extension and contraction. The two shock absorbers are arranged on the front and rear sides of the load-bearing girder, respectively, and are used to buffer the vertical bouncing of the tire.

[0008] Further, the power assembly comprises a wheel hub motor, and the two tires are respectively connected with a separate wheel hub motor.

[0009] Further, the power assembly further comprises a driving motor. The lower end of the load-bearing girder is provided with a motor support, the driving motor is arranged in the motor support, and the driving motor is detachably connected with the transmission rod, and is used to drive the tire to rotate.

[0010] Further, the loading frame is provided with a loading area and a power battery placement area above, a partition plate is arranged between the loading area and the power battery placement area, and the power battery placement area is arranged close to the rear of the loading frame.

[0011] According to another aspect of the present application, an intelligent following method of the intelligent perception following transport vehicle is provided, which is applied to the intelligent perception following transport vehicle described above; the method comprises: S100: in response to the posture adjustment instruction, the current inclination angle P of the suspension assembly is obtained by the IMU, and the current tension Fc in the vertical direction of the transport vehicle is obtained by the tension sensor; the inclination angle is the inclination angle relative to the vertical direction, if the current inclination angle is the forward inclination angle, P < 0, if the current inclination angle is the backward inclination angle, P > 0; S200: if P ∉ [P1, P2] and P < 0, the length of the angle adjusting assembly is shortened, and the P of the suspension assembly is continuously obtained; P1 is the forward inclination angle threshold value, and P2 is the backward inclination angle threshold value; S300: when P=P1, if Fc>F1, continue to control the angle adjusting assembly to shorten its length, and continue to acquire Fc; F1 is a lifting force threshold value; S400: if P=P2 or Fc=F1, stop the telescopic motion of the angle adjusting assembly.

[0012] Further, the method further comprises: S410: if P=P2 and Fc>F1, stop the telescopic motion of the angle adjusting assembly, and acquire the distance L between the sliding part and the front limit point of the slide rail travel in the slide rail assembly; S420: if L>L1, control the screw driving assembly to rotate to move the sliding part to the preset distance close to the front limit point of the slide rail travel; L1 is a preset distance threshold value; S430: after the sliding part is moved, the steps of S100 to S420 are re-executed.

[0013] Further, the method further comprises: In response to the following instruction, the tensile force sensor is used to acquire the tensile forces Fs1 and Fs2 of the two holding points in the horizontal direction of the transport vehicle; Fs1 is the tensile force of the left holding point in the horizontal direction of the transport vehicle; Fs2 is the tensile force of the right holding point in the horizontal direction of the transport vehicle; If , and F3, the power assembly is controlled to apply the same driving force Fq to the two tires; Fq satisfies the following conditions: ; Wherein, F2 is a tensile force difference threshold value, F3 is a basic tensile force threshold value, and k1 is a power conversion coefficient; if Fq<0, the driving force is a forward inhibiting driving force; if Fq>0, the driving force is a forward assisting driving force.

[0014] The present application has at least one of the following beneficial effects: In the present application, by setting independent suspension for each tire, the car body shaking is reduced when the car passes through complex pothole wild terrain, the car body stability is improved, and the energy consumed by the person to keep the car body balanced is reduced, thereby achieving the effect of saving labor.

[0015] Meanwhile, due to the difference in height of different people, the tilting angle of the trolley is also different after holding the trolley. In the present application, the tire and the frame of the loading vehicle body are connected through the suspension assembly, so in the case of different tilting angles of the vehicle body, it is very likely that the tilting angle of the suspension assembly exceeds the reasonable working tilting angle range of the suspension, and thus the damping effect cannot be achieved. Based on this, the present application also provides an angle adjusting assembly to adjust the tilting angle of the suspension assembly. Specifically, the current angle of the suspension assembly relative to the vertical plane can be changed through the angle adjusting assembly, so that the suspension assembly can be within the reasonable working tilting angle range even if the loading frame itself has different tilting angles, thereby playing an effective damping role, thereby reducing the energy consumed by the person to keep the vehicle body balanced, and achieving the effect of saving labor.

[0016] In addition, since the mechanical model of the transport vehicle in the present application is a lever model with the resistance point and the force point on the same side of the fulcrum, in order to reduce the force of the force point, a fulcrum adjusting assembly is also provided to adjust the position of the connecting point between the suspension and the loading frame. Under the joint action of the fulcrum adjusting assembly and the angle adjusting assembly, the position of the fulcrum (i.e. the wheel) in the lever model can be adjusted, thereby increasing the ratio of the force arm from the fulcrum to the force point to the force arm between the fulcrum and the resistance point, to reduce the force of the person, achieve the effect of saving labor, and reduce the physical energy consumed by the person in the process of controlling the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0018] Figure 1 A general structure schematic diagram of an intelligent perception following type transport vehicle provided by the embodiment of the present application.

[0019] Figure 2 Another general structure schematic diagram of an intelligent perception following type transport vehicle provided by the embodiment of the present application.

[0020] Figure 3 A connection structure schematic diagram between a pair of tires, a suspension assembly, a power assembly, a fulcrum adjusting assembly and an angle adjusting assembly provided by the embodiment of the present application.

[0021] Figure 4 A connection structure schematic diagram of the suspension assembly provided by the embodiment of the present application.

[0022] Figure 5 A lever model principle schematic diagram of the transport vehicle provided by the embodiment of the present application.

[0023] Figure 6 The overall structure diagram of the holding part when the transport vehicle provided by the embodiment of the present application is provided with a wearable structure.

[0024] Figure 7 The flowchart of the intelligent following method of the intelligent and perceptual following type transport vehicle provided by the embodiment of the present application. ACCOMPA

[0025] 1, loading frame; 2, tire; 3, angle adjusting assembly; 4, suspension assembly; 41, shock absorber; 42, steering knuckle; 43, transmission rod; 44, wheel angle adjusting rod; 45, load-bearing girder; 46, driving motor; 51, screw rod driving assembly; 52, slide rail assembly; 53, fulcrum rotating shaft. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person skilled in the art without creative work fall within the protection scope of the present application.

[0027] As a possible embodiment of the present application, as shown in Figure 1 and Figure 2 , an intelligent and perceptual following type transport vehicle is provided, which comprises a loading frame 1, a pair of tires 2, a suspension assembly 4, a power assembly, a fulcrum adjusting assembly, an angle adjusting assembly 3, a tension sensor and an IMU (Inertial Measurement Unit).

[0028] The tension sensor is arranged at the human force holding part of the loading frame 1, and is used to obtain the horizontal direction tension and the vertical direction tension of the transport vehicle. Specifically, the tension sensor is a strain gauge type force sensor.

[0029] Specifically, a plurality of strain gauges can be installed at the handle of the human-powered tricycle to detect the distribution of the tension when the human-powered tricycle is pulled. In actual use, the human usually exerts two directions of force on the transport vehicle, specifically, exerts tension or resistance in the horizontal direction to control the forward or backward movement of the vehicle, and exerts upward lifting force in the vertical direction to lift the handle to a suitable height.

[0030] In addition, as shown in Figure 6As shown, in the present example, the wearable structure can also be arranged to be connected with the handlebar of the transport vehicle. In this way, the transport personnel can control the forward or backward movement of the vehicle by wearing the corresponding push-pull strap. With the help of the structure, the force for controlling the vehicle body can be distributed to multiple parts of the human body, thereby avoiding the consumption of human power caused by controlling the vehicle posture only by the arms, and making the human power more labor-saving when controlling the forward or backward movement of the vehicle. In the structure, strain gauges can be attached to the part of the push-pull strap and the connection between the strap and the handlebar to measure the control force applied. Of course, other existing tension sensors can also be arranged in the present example to measure the required tension.

[0031] A pair of tires 2 are connected to the bottom of the loading frame 1 through suspension assemblies 4. A power assembly is connected with the tires 2 for independently driving the two tires 2 to rotate, respectively. Specifically, the power assembly includes hub motors, and the two tires 2 are connected with separate hub motors, respectively.

[0032] To enhance the off-road performance, the tires 2 used in the present application are off-road tires 2 with more prominent and bulky patterns. In addition to the patterns on the circumferential wall of the tires 2, the outer side wall of the tires 2 is also provided with corresponding patterns, which can improve the grip of the tires 2 on muddy roads in the wild, thereby enhancing the escape ability. In addition, in terms of power arrangement, two hub motors are respectively arranged to control the movement of the two tires 2, thereby improving the escape ability of the vehicle.

[0033] Further, as shown in the figure, Figure 4 the power assembly also includes a drive motor 46.

[0034] The lower end of the load-bearing beam 45 is provided with a motor support, and the drive motor 46 is arranged inside the motor support and is detachably connected with the transmission rod 43 for driving the tires 2 to rotate.

[0035] Since the transport vehicle in the present example is often used in complex terrain in the wild, the power of the two hub motors may not be sufficient to provide sufficient driving force for the transport vehicle to escape or climb uphill when the vehicle is stuck or climbing. Therefore, a set of backup drive motors 46 is arranged. When more driving force is needed, the backup drive motor 46 is connected with the tire 2 through the transmission rod 43, thereby providing more driving force. In addition, by redundantly arranging the driving components, when a driving component fails, the other driving components can continue to drive the tires 2 to move, thereby improving the adaptability of the transport vehicle in the wild in the present example.

[0036] Further, as shown in the figure, Figure 2 the loading frame 1 is provided with a loading area and a power battery placement area above it, and a partition is arranged between the loading area and the power battery placement area. The power battery placement area is arranged near the rear of the loading frame 1.

[0037] The transport vehicle in this example is similar in structure to a handcart. The mechanical model of the vehicle structure is a lever model in which the resistance point and the force application point are located on the same side of the fulcrum, as shown in Figure 5 . Specifically, the force application point is where a person applies force, the resistance point is usually where the center of gravity of the loaded weight is located, and the fulcrum is where the wheel is located. Typically, the wheel is close to the rear of the vehicle. Therefore, to further shorten the distance between the resistance point and the fulcrum, a heavy object such as a power battery is arranged at the rear of the vehicle frame, thereby moving the center of gravity of the entire vehicle loaded with the weight to the rear, reducing the resistance arm, and reducing the size of the force required at the force application point.

[0038] The IMU is arranged on the suspension assembly 4 and is used to obtain the inclination angle of the suspension assembly 4. The IMU contains a gyroscope + accelerometer and is a sensor module for measuring the acceleration and angular velocity of an object. It is a core component for realizing intelligent functions such as attitude sensing, motion control, and navigation positioning. The IMU can obtain the size of the inclination angle between the suspension assembly 4 and the vertical plane. Typically, the inclination angle between the suspension assembly 4 and the vertical plane is within a small range, for example, within an interval of plus or minus twenty degrees. Within this interval, the shock absorber 41 in the suspension assembly 4 can be almost in a vertical state, thereby effectively relieving the vibration and energy transmitted by the tire 2 when it jumps up and down, so that the vehicle frame above remains stable and does not shake. However, if the inclination angle between the suspension assembly 4 and the vertical plane is too large, the angle between the shock absorber 41 and the vertical plane will also be too large. When the vertical direction jump transmitted by the wheel reaches the shock absorber 41, the shock absorber 41 cannot absorb the corresponding energy and shake by itself, thereby failing to achieve the shock absorption effect, resulting in the vehicle body shake cannot be effectively reduced. Thus, the IMU can be used to monitor the inclination angle of the suspension assembly 4 in real time to ensure that it is in the best working state.

[0039] Specifically, as shown in Figure 3 and Figure 4 , the suspension assembly 4 includes a load-bearing girder 45 and two sub-suspension groups.

[0040] The two sub-suspension groups are symmetrically arranged at the two ends of the load-bearing girder 45, and each sub-suspension group is connected to one tire 2. The top of the load-bearing girder 45 is rotationally connected to the fulcrum shaft 53.

[0041] As shown in Figure 4 , the sub-suspension group includes two shock absorbers 41, a transmission rod 43, a wheel angle adjusting rod 44, and a knuckle 42.

[0042] The outer side of the knuckle 42 is connected to the tire 2, and the two ends of the shock absorber 41, the transmission rod 43, and the wheel angle adjusting rod 44 are connected between the load-bearing girder 45 and the knuckle 42.

[0043] The transmission rod 43 is used to limit the lateral distance between the knuckle 42 and the load beam 45. In this example, the transmission rod 43 can also be used to transmit the driving force of the driving motor 46, so the transmission rod 43 can be connected with the driving shaft of the tire 2. When the driving motor 46 is detached from the transmission rod 43, the transmission rod 43 is in an idle state under the driving of the in-wheel motor. Since the transmission rod 43 will be in an unstable state of up and down jumping during movement, universal joints are used at both connections of the transmission rod 43 to prevent the transmission rod 43 from being stuck during movement, thereby affecting the power output of the driving motor 46. Of course, in this example, the transmission rod 43 can also be disconnected from the driving shaft of the in-wheel motor, so that in the normal state, only the transmission rod 43 has the function of limiting the lateral distance variation, but does not have the transmission function. When the standby driving motor 46 and the in-wheel motor are required to provide driving force together, the two ends of the transmission rod 43 are connected with the transmission shaft of the standby motor and the in-wheel motor respectively.

[0044] The wheel angle adjusting rod 44 adjusts the inclination angle of the knuckle 42 by its own extension and retraction. One end of the wheel angle adjusting rod 44 is connected to the load beam, and the other end is connected to the connecting foot above the knuckle 42. By adjusting the length of the wheel angle adjusting rod 44 itself, the distance between the tire 2 and the vertical plane can be adjusted. The two tires 2 can be in an inward inclination or outward inclination state to adapt to different operating environments. For example, when driving on unpaved roads (such as mud, gravel, sand), a moderate positive camber (i.e., the tire 2 is in an outward inclination state) can allow more contact with the ground on the outside of the tire 2.

[0045] The two shock absorbers 41 are arranged on the front and rear sides of the load beam 45 respectively, and are used to buffer the vertical jumping of the tire 2.

[0046] By providing independent suspension assemblies 4 for the two tires 2 respectively, the vertical jumping of the tire 2 when running on unpaved roads can be effectively filtered, thereby reducing the left and right shaking of the vehicle body, reducing the power consumed by the human body to control the posture of the vehicle body, and achieving the effect of saving labor.

[0047] As shown in Figure 3 The fulcrum adjusting assembly includes a sliding rail assembly 52, a screw rod driving assembly 51, and a fulcrum rotating shaft 53.

[0048] The sliding rail assembly 52 and the screw rod driving assembly 51 are fixedly arranged at the bottom of the loading frame 1, and the sliding direction of the sliding rail assembly 52 and the driving direction of the screw rod driving assembly 51 are the same as the front-rear axial direction of the loading frame 1. The fulcrum rotating shaft 53 is rotatably arranged in the sliding part of the sliding rail assembly 52 and the near-vehicle end of the suspension assembly 4, so that the suspension assembly 4 is rotatably connected with the loading frame 1. The fulcrum rotating shaft 53 is connected with the moving part of the screw rod driving assembly 51, and the screw rod driving assembly 51 is used to drive the fulcrum rotating shaft 53 to move along the front-rear axial direction of the loading frame 1.

[0049] The fulcrum adjusting assembly can be used to adjust the front and back positions of the connection between the load-bearing girder and the frame of the suspension assembly 4, thereby moving the tires 2 forward and backward, i.e., moving the fulcrum of the lever forward and backward. Generally, in the lever model of the present example, the resistance point is closer to the fulcrum position than the force point, i.e., the resistance arm is smaller than the force arm. In the present embodiment, the fulcrum adjusting assembly can move the fulcrum to the side close to the resistance by a corresponding distance. Although this distance of movement will shorten the resistance arm and the force arm by the same amount, the ratio of the resistance arm to the force arm after the movement will be smaller than the ratio of the resistance arm to the force arm before the movement, thereby reducing the size of the force after the movement of the fulcrum, and achieving the effect of labor saving.

[0050] As shown in Figure 5 , taking the original force arm as a, the resistance arm as b, and the reduction of the arm of the tires 2 after movement as c, a > b > c > 0, the following is explained: Since c > 0, a > b ⇒ a - b > 0, and b > c ⇒ b - c > 0, it is , i.e. .

[0051] Specifically, a = 10, b = 5, and c = 2. The ratio of the force arm to the resistance arm before shortening is 10 / 5 = 2, and the ratio of the force arm to the resistance arm after shortening is (10-2) / (5-2) = 2.67. Therefore, by adjusting the movement of the fulcrum adjusting assembly, the ratio of the force arm to the resistance arm can be increased, and correspondingly, the size of the force in the vertical direction applied by the force point can be reduced.

[0052] The two ends of the angle adjusting assembly 3 are connected to the near-wheel end of the suspension assembly 4 and the bottom of the loading frame 1, respectively. The angle adjusting assembly 3 drives the suspension assembly 4 to rotate around the fulcrum pivot 53 through its own extension and contraction, to adjust the angle of the suspension assembly 4. Specifically, the angle adjusting assembly 3 includes an electric push rod or a hydraulic rod.

[0053] The main function of the angle adjusting assembly 3 is to adjust the inclination angle between the suspension assembly 4 and the vertical plane, so that it is at the best working angle. At the same time, since the upper end of the suspension assembly 4 is rotationally connected to the frame, when the angle adjusting assembly 3 adjusts the angle of the suspension assembly 4 through its own extension and contraction, it will drive the tires 2 below to move forward and backward relative to the frame, thereby achieving the adjustment of the fulcrum of the lever.

[0054] As another embodiment of the present application, as shown in Figure 7 , an intelligent following method of an intelligent perception following type transport vehicle is provided, which is applied to the intelligent perception following type transport vehicle described above. The method comprises: S100: In response to the posture adjustment instruction, the current inclination angle P of the suspension assembly 4 is obtained by the IMU, and the current pulling force Fc in the vertical direction of the transport vehicle is obtained by the pulling force sensor. The inclination angle is the inclination angle relative to the vertical direction. If the current inclination angle is the forward inclination angle, P < 0; if the current inclination angle is the backward inclination angle, P > 0.

[0055] In the present example, the posture adjustment instruction can be triggered manually, or a plurality of monitoring periods are set, the average inclination angle of the suspension assembly 4 in each period is calculated, and the average inclination angle is compared with the preset angle range. If the average inclination angle is within the preset angle range, no posture adjustment instruction is issued; if it is outside the preset angle range, a posture adjustment instruction is issued. The monitoring period can be one second.

[0056] When moving on an unpaved road, the sideways posture is often difficult to maintain as stable as on a paved road. In addition, because the front end is manually controlled, the person holding it may occasionally cause the trolley to pitch when adjusting his / her own posture. This operation causes temporary and random changes in the posture of the trolley, and after adjustment, the trolley will return to its previous state, and the corresponding suspension assembly 4 will also return to the previously adjusted posture. In this state, there is no need to adjust the inclination angle of the suspension.

[0057] However, during the operation of the trolley, the person holding it may also be replaced. Because the holding height of the person holding it is different, it will change the pitch angle of the trolley, and thus cause the inclination angle of the suspension to deviate from the optimal working angle range. Or during the operation, it changes from a flat road to an uphill or downhill road, at which time the pitch of the trolley will change greatly, and also cause the inclination angle of the suspension to deviate from the optimal working angle range. In this state, the inclination angle of the suspension changes and will be maintained for a long time and continuously, so it is necessary to adjust the inclination angle of the suspension again to make it reach the optimal working state.

[0058] Therefore, by setting a detection period of a certain length, the above two different change states can be effectively distinguished to avoid triggering unnecessary adjustment operations.

[0059] S200: If P ∉ [P1, P2] and P < 0, control the angle adjustment assembly 3 to shorten its length, and continuously obtain P of the suspension assembly 4. P1 is the forward inclination angle threshold, such as P1 = -15°, and P2 is the backward inclination angle threshold, such as P2 = 15°.

[0060] S300: When P = P1, if Fc > F1, continuously control the angle adjustment assembly 3 to shorten its length, and continuously obtain Fc. F1 is the lifting force threshold, such as F1 = 10 N.

[0061] S400: If P = P2 or Fc = F1, stop the extension and retraction movement of the angle adjustment assembly 3.

[0062] In the above steps, if P∉[P1, P2] and P<0, it indicates that the current forward inclination angle of the suspension assembly 4 is too large and needs to be adjusted. To reduce the forward inclination angle, the length of the angle control assembly needs to be shortened. In this adjustment process, on the one hand, the forward inclination angle of the suspension assembly 4 gradually decreases and gradually approaches P1; on the other hand, because the fulcrum moves forward, the lifting force of the holding end upward also gradually decreases and gradually approaches F1. Therefore, in the adjustment process, the inclination angle of the suspension assembly 4 reaching P2 or the lifting force reaching F1 can be used as a cutoff condition to control whether the angle adjustment assembly 3 continues to be shortened, thereby ensuring that the suspension assembly 4 is at the optimal working angle while minimizing the lifting force of the human holding end as much as possible to achieve the effect of saving labor. At the same time, because the inclination angle of the suspension assembly 4 is reduced, the distance between the vehicle frame and the ground will be raised, thereby further improving the passing ability of the vehicle on unpaved roads.

[0063] In this example, the posture of the transport trolley is adjusted, on the one hand, the inclination angle of the suspension assembly 4 is adjusted to make the suspension assembly 4 reach the optimal working state; on the other hand, the change of the inclination angle of the suspension assembly 4 will affect the change of the front and rear position of the tire 2 relative to the vehicle frame, thereby affecting the position of the fulcrum in the lever model, which will also affect the size of the lifting force required to lift the trolley by the human hand. In this example, the above two effects can be achieved at the same time through the above adjustment.

[0064] Further, the method further comprises: S410: If P=P2 and Fc>F1, stop the extension and contraction movement of the angle adjustment assembly 3, and at the same time obtain the distance L between the sliding part in the sliding rail assembly 52 and the front limit point of the sliding rail stroke.

[0065] S420: If L>L1, control the screw drive assembly 51 to rotate to move the sliding part by a preset distance towards the front limit point of the sliding rail stroke. L1 is a preset distance threshold. In actual use, as the suspension assembly 4 gradually moves forward at the vehicle frame connection point, it will cause the lowest point installed at the rear of the loading vehicle frame 1 to gradually decrease. In view of this, in order to consider the passing ability of the vehicle, a front limit point of the sliding rail stroke will also be set.

[0066] S430: After the sliding part moves, the steps of S100 to S420 are re-executed.

[0067] In the present application, the main goal is to save manpower. Therefore, after the current position of the angle adjusting assembly 3 is adjusted, if the lifting force of the holding end cannot be effectively reduced when the inclination angle of the suspension assembly 4 reaches the maximum backward inclination angle, the fulcrum adjusting assembly can be started to move the connection point between the suspension assembly 4 and the loading frame 1 forward, so that the inclination angle of the suspension assembly 4 becomes a forward inclination angle again. At this time, the steps S100 to S420 can be re-executed, and after multiple cycles of the above steps, the lifting force of the holding end can be effectively controlled within a reasonable range when the suspension assembly 4 is in the best working state.

[0068] Further, it also includes: S510: In response to the following instruction, the tensile forces Fs1 and Fs2 of the two holding points on the horizontal direction of the transport vehicle are obtained by the tensile force sensor. Fs1 is the tensile force of the left holding point on the horizontal direction of the transport vehicle; Fs2 is the tensile force of the right holding point on the horizontal direction of the transport vehicle.

[0069] The following instruction in this example can be triggered by human initiative, or according to the posture adjusting instruction, a plurality of monitoring periods are set, and the average value of the horizontal tensile force of the personnel in each period is calculated, that is, Fs1 and Fs2 are the average value of the tensile force in a certain period. By setting a detection period of a certain length, the following instruction can be avoided. Triggered by mistake, it can also reduce the adjustment frequency of the motor driving force, and avoid frequent interruptions during the operation of the transport vehicle.

[0070] S520: If , and , the power assembly applies the same driving force Fq to the two tires 2. Fq satisfies the following conditions: .

[0071] Wherein, F2 is the tensile force difference threshold, F3 is the basic tensile force threshold, and k1 is the power conversion coefficient. If Fq < 0, the driving force is the forward inhibition driving force. If Fq > 0, the driving force is the forward auxiliary driving force.

[0072] S530: If , and F3, the power assembly applies different driving forces Fq1 and Fq2 to the two tires 2 respectively. Fq1 is the driving force applied to the left tire 2; Fs2 is the driving force applied to the right tire 2; Fq1 and Fq1 satisfy the following conditions: ; .

[0073] When the person pulls the trolley on the flat ground with the standard posture, it has the following characteristics: Both hands are symmetrically distributed on both sides of the handle; the center of gravity of the body is in the middle; the pulling force is consistent (in the direction of the trolley forward).

[0074] At this time: the purpose is to maintain the straight-line motion of the trolley and avoid yaw, so the pulling forces of the left and right hands are approximately equal, and the difference in pulling force is approximately 0% ~10% of the total pulling force. Therefore, the size of F2 can be set according to the above principle, such as F2 = 3N.

[0075] By comparing F1 with F2, it can be determined whether the trolley is currently in a straight-line state or a turning state. If F1 < F2, it indicates that the trolley is currently in a straight-line state. In this state, the driving forces of the two tires 2 need to be kept consistent, so that the trolley can better maintain the straight-line state. If F1 > F2, it indicates that the trolley is currently in a turning state. In this state, the driving forces of the two tires 2 need to be kept inconsistent, so that the trolley can better maintain the turning state. Specifically, in calculating the driving force applied to the two tires 2, the difference between the current horizontal pulling force of the person and the set basic pulling force threshold value is mainly relied on. Generally, the larger the difference, the more pulling force the person exerts, that is, the more driving force the hub motor needs to compensate. In this example, based on the linear function set according to the difference, the additional pulling force exerted by the person can be converted into the driving force size required by the tire 2 to be compensated. In addition, by calculating the ratio of the horizontal pulling force to its absolute value (the ratio is +1 or -1), it can be determined whether the pulling force exerted by the person is a driving force to drive the trolley forward or a resistance to hinder the trolley forward, so as to realize the compensation of the hub motor to the pulling force of the person, and thus achieve the effect of saving the labor of the person.

[0076] The present application combines the above-mentioned multiple schemes to intelligently perceive the running state of the transport trolley expected to be achieved by the pulling person, and timely adjusts each component, so that the transport trolley can timely present the corresponding motion state according to the intention of the pulling person, improve the intelligent following performance of the transport trolley, and make it more convenient and intelligent to use.

[0077] In addition, although the steps of the method in the present disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in this specific order, or that all the steps shown must be performed to achieve the desired results. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step, and / or one step can be divided into multiple steps, etc.

[0078]

[0079] ​Those skilled in the art can clearly understand the example embodiments described herein through the above description of the example embodiments that the example embodiments described herein can be implemented by software or by software in combination with necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product. The software product can be stored in a non-volatile storage medium (which can be a CD-ROM, a U disk, a mobile hard disk, or the like) or on a network, and includes a plurality of instructions to enable a computing device (which can be a personal computer, a server, a mobile terminal, or a network device, or the like) to execute the method according to the embodiments of the present disclosure.

[0080] The above merely describes specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed by the present application can be easily conceived by those skilled in the art, and should be encompassed within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An intelligent, sensory-aware, following transport vehicle, characterized in that, include: The vehicle is equipped with a frame, a pair of tires, suspension components, power components, pivot adjustment components, angle adjustment components, a tension sensor, and an IMU. The tension sensor is installed on the manual gripping part of the loading frame to obtain the horizontal and vertical tension forces on the transport vehicle. A pair of tires are each connected to the bottom of the loading frame via a suspension assembly; the power assembly is connected to the tires and is used to independently drive the two tires to rotate. An IMU is installed on the suspension assembly to obtain the tilt angle of the suspension assembly; The fulcrum adjustment assembly includes a slide rail assembly, a screw drive assembly, and a fulcrum shaft; The slide rail assembly and the screw drive assembly are both fixedly mounted on the bottom of the loading frame. The sliding direction of the slide rail assembly and the driving direction of the screw drive assembly are the same as the front-rear axial direction of the loading frame. The pivot shaft is rotatably mounted through the sliding part of the slide rail assembly and the near-vehicle end of the suspension assembly, so that the suspension assembly is rotatably connected to the loading frame. The pivot shaft is connected to the moving part of the screw drive assembly, and the screw drive assembly is used to drive the pivot shaft to move along the front-rear axial direction of the loading frame. The two ends of the angle adjustment component are respectively connected to the near wheel end of the suspension component and the bottom of the loading frame. The angle adjustment component drives the suspension component to rotate around the pivot axis through its own telescopic movement, so as to adjust the angle of the suspension component.

2. The smart-aware follow-bot vehicle of claim 1, wherein, The angle adjustment assembly includes an electric actuator or a hydraulic actuator.

3. The smart-aware follow-bot vehicle of claim 1, wherein, The tensile sensor is a strain gauge type force sensor.

4. The smart-aware follow-bot vehicle of claim 1, wherein, The suspension assembly includes a load-bearing main beam and two sub-suspension assemblies; Two sub-suspension assemblies are symmetrically arranged at both ends of the load-bearing beam, and each sub-suspension assembly is connected to a tire; the top of the load-bearing beam is rotatably connected to the pivot shaft. The sub-suspension assembly includes two shock absorbers, a drive rod, a wheel angle adjustment rod, and a steering knuckle; The outer side of the steering knuckle is connected to the tire, and the two ends of the shock absorber, transmission rod, and wheel angle adjustment rod are respectively connected between the load-bearing beam and the steering knuckle; The transmission rod is used to limit the lateral distance between the steering knuckle and the load-bearing beam; The wheel angle adjusting rod adjusts the tilt angle of the steering knuckle by extending and retracting itself; The two shock absorbers are respectively arranged on the front and rear sides of the load-bearing beam to buffer the vertical bounce of the tires.

5. The smart-aware follow-bot vehicle of claim 4, wherein, The power unit includes hub motors, with each of the two tires connected to a separate hub motor.

6. The smart-aware follow-bot vehicle of claim 5, wherein, The power assembly also includes a drive motor; A motor bracket is provided at the lower end of the load-bearing beam, and the drive motor is located inside the motor bracket. The drive motor is detachably connected to the transmission rod and is used to drive the tire to rotate.

7. The smart-aware follow-bot vehicle of claim 1, wherein, The loading frame is provided with a loading area and a power battery placement area on top, and a partition is provided between the loading area and the power battery placement area. The power battery placement area is located near the rear of the loading frame.

8. An intelligent following method of an intelligent perception following transport vehicle, characterized by, The method is applied to the intelligent sensing following transport vehicle according to any one of claims 1-7; the method includes: S100: in response to the posture adjustment instruction, acquiring the current inclination angle P of the suspension assembly through the IMU and acquiring the current pulling force Fc on the vertical direction of the transport vehicle through the pulling force sensor; the inclination angle is the inclination angle relative to the vertical direction, if the current inclination angle is the forward inclination angle, then P<0, if the current inclination angle is the backward inclination angle, then P>0; S200: if P∉[P1, P2] and P<0, then controlling the angle adjusting assembly to shorten its length, and continuously acquiring P of the suspension assembly; P1 is the forward inclination angle threshold, and P2 is the backward inclination angle threshold; S300: when P=P1, if Fc>F1, then continuously controlling the angle adjusting assembly to shorten its length, and continuously acquiring Fc; F1 is the lifting force threshold; S400: if P=P2 or Fc=F1, then stopping the extension and retraction movement of the angle adjusting assembly.

9. The intelligent following method of the intelligent perception following transport vehicle according to claim 8, wherein, The method further comprises: S410: if P=P2 and Fc>F1, then stopping the extension and retraction movement of the angle adjusting assembly, and simultaneously acquiring the distance L between the sliding part of the slide rail assembly and the front limit point of the slide rail stroke; S420: if L>L1, then controlling the screw drive assembly to rotate, so as to move the sliding part by a preset distance towards the direction of the front limit point of the slide rail stroke; L1 is the preset distance threshold; S430: after the movement of the sliding part is completed, the steps of S100 to S420 are re-executed.

10. The intelligent following method of the intelligent perception following transport vehicle according to claim 8, wherein, Further comprising: in response to the following instruction, acquiring the current pulling forces Fsl and Fs2 on the horizontal direction of the transport vehicle respectively corresponding to the two holding points through the pulling force sensor; Fsl is the pulling force on the horizontal direction of the transport vehicle corresponding to the left holding point; Fs2 is the pulling force on the horizontal direction of the transport vehicle corresponding to the right holding point; If , and F3, then the power assembly is controlled to apply the same driving force Fq to both tires; Fq satisfies the following condition: ； wherein, F2 is the pulling force difference threshold, F3 is the basic pulling force threshold, and k1 is the power conversion coefficient; if Fq<0, then the driving force is the forward inhibition driving force; if Fq>0, then the driving force is the forward auxiliary driving force.

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