An active adjustable suspension travel mobile robot chassis

Abstract

The utility model discloses a kind of mobile robot chassis of active adjustable suspension stroke, to solve the problem of existing robot chassis suspension stroke unadjustable or adjusting mechanism complex, high cost, insufficient reliability. The technical scheme of the utility model includes: chassis rack, front wheel, drive wheel, rear wheel, and suspension assembly (including drive wheel rocker arm) with drive wheel and rear wheel movable connection, and adjusting stroke device;The adjusting stroke device is equipped with electric push rod and the sliding limit piece cooperation with drive wheel rocker arm, and electric push rod drives sliding limit piece to move to change the movable range of drive wheel rocker arm, to adjust suspension stroke.The utility model can actively adjust suspension stroke, adapt to different working conditions, improve motion stability, obstacle-crossing ability and safety, and simple structure, lower cost, higher reliability.

Description

Technical Field

[0001] This utility model relates to the field of mobile robot technology, and more specifically, to a mobile robot chassis capable of actively adjusting its suspension travel. Background Technology

[0002] With the development of technologies such as the Internet of Things, AI, and autonomous driving, the intelligence level of robots is increasing year by year. They can not only make autonomous decisions and move, but also adapt to complex and dynamic external environments. The mobile robot chassis serves as the robot's carrier and plays a crucial role in the robot's task execution. In recent years, mobile robots have been increasingly used in industries such as transportation, healthcare, services, education, and entertainment, demonstrating significant economic and social value. Examples include food delivery robots in restaurants, medical equipment delivery robots, and embodied robots used in home and commercial environments. Therefore, mobile robots have a wide range of applications in many fields.

[0003] Indoor mobile robot chassis typically employ a four-wheel eight-wheel drive (four servo wheels) or a six-wheel two-wheel drive differential wheel layout. Four-wheel eight-wheel drive (four servo wheels) chassis are relatively large and heavy, complex to control, and expensive, offering good longitudinal stability but relatively low lateral stability. Six-wheel two-wheel drive differential chassis usually require suspension to allow the drive wheels sufficient traction for overcoming obstacles and climbing slopes. Chassis layouts with omnidirectional wheels and suspension, or independent suspension on the drive wheels, or a combination of both, are prone to tilting in the direction of travel during sudden braking (nodding), potentially causing tipping.

[0004] Mobile robots, especially home-use robots, face complex motion conditions. These conditions include traversing steps, level wooden floors, thick carpeted surfaces, and ramps. Furthermore, these conditions present extreme challenges such as changes in robot posture and elevation, causing shifts in the robot's center of gravity, which reduce stability and increase the risk of tipping over. Currently, most mobile robot chassis lack actively adjustable suspension travel mechanisms specifically designed to address this issue. Traditional mobile robots largely rely on suspension to passively eliminate tilt, lacking actuator control systems that actively adjust suspension travel. Chassis types vary significantly depending on the specific working conditions and travel requirements. Current chassis types are specifically designed for certain robot operating conditions, and existing non-adjustable suspension systems struggle to meet diverse needs, making it difficult to simultaneously achieve agile obstacle avoidance, obstacle crossing, slope climbing, and stable braking without tilting.

[0005] Existing chassis with adjustable suspension travel or stiffness coefficient mostly use electromagnetic damping or pneumatic damping, which involves many components, complex control, high cost, and relatively low reliability.

[0006] Therefore, it is necessary to research and develop chassis suspension components and stroke adjustment devices for mobile robots to solve the motion and safety problems of existing mobile robot chassis under different working conditions. Utility Model Content

[0007] The main purpose of this utility model is to provide a mobile robot chassis with an actively adjustable suspension stroke, which aims to solve the problems in the prior art where the suspension stroke of robot chassis is usually not automatically adjustable, or even if it is adjustable, the adjustment mechanism is complex, costly, and unreliable.

[0008] To achieve the above objectives, this utility model provides a mobile robot chassis with an actively adjustable suspension stroke, comprising: a chassis frame; at least two front wheels fixedly mounted on the front of the chassis frame; at least two drive wheels located in the middle of the chassis frame; at least two rear wheels located at the rear of the chassis frame; at least two suspension assemblies respectively mounted on the chassis frame, the suspension assemblies being movably connected to the drive wheels and the rear wheels, each suspension assembly including a drive wheel rocker arm connected to the drive wheel; and at least one stroke adjustment device mounted on the chassis frame, the stroke adjustment device including an electric push rod and a sliding limit member, the electric push rod being connected to the sliding limit member and driving the sliding limit member to move, the sliding limit member being used to cooperate with the drive wheel rocker arm to change the range of motion of the drive wheel rocker arm relative to the chassis frame, thereby adjusting the suspension stroke of the suspension assembly.

[0009] In some preferred embodiments, the front wheel is a front swivel wheel, and the rear wheel is a rear swivel wheel. The suspension assembly further includes a rear swivel wheel rocker arm connected to the rear swivel wheel, and a linkage connecting the drive wheel rocker arm and the rear swivel wheel rocker arm. Both the drive wheel rocker arm and the rear swivel wheel rocker arm are hinged to the suspension base, forming a four-bar linkage, which enables the rear swivel wheel to move in conjunction with the drive wheel. This design allows the drive wheel and the rear swivel wheel to move in tandem, better adapting to uneven road surfaces.

[0010] In some preferred embodiments, the stroke adjustment device further includes a limiting member slide seat, which is fixed to the chassis frame. The sliding limiting member is installed within the limiting member slide seat and slides along a defined straight path. This ensures the stability and accuracy of the sliding limiting member's movement.

[0011] In some preferred embodiments, a soft rubber buffer layer is provided on the side of the sliding limit member that contacts the drive wheel rocker arm, which can buffer impact and reduce noise.

[0012] In some preferred embodiments, a rolling wheel is provided between the bottom of the sliding limiter and the chassis frame or the limiter slide seat to reduce sliding friction.

[0013] In some preferred embodiments, the suspension assembly further includes a tension spring connected between the drive wheel rocker arm and a tension spring hanger fixed to the chassis frame, for applying downward pressure to the drive wheel and enhancing the drive wheel's grip.

[0014] In some preferred embodiments, the chassis is further equipped with an inertial measurement unit (IMU) and sensors, and the robot body is equipped with an AI central control unit. The AI ​​central control unit is used to receive attitude information fed back by the inertial measurement unit (IMU) and environmental signals collected by the sensors, and to send command signals to the electric push rod in the stroke adjustment device according to a preset algorithm to control the extension or retraction of the sliding limit member, thereby realizing the switching adjustment of the suspension stroke between long stroke and short stroke states.

[0015] In some preferred embodiments, the body of the sliding limiter is made of a metal material, preferably an aluminum alloy, to ensure that it has sufficient structural strength and stability when engaged with the drive wheel rocker arm.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. High adaptability and safety: The suspension travel of this utility model can be actively adjusted in two levels, which can adapt to common level ground and extreme working conditions such as changes in the robot's center of gravity, significantly improving the robot's movement safety and body stability under different road conditions.

[0018] 2. Strong obstacle-crossing and ditch-crossing capabilities while maintaining stability: By actively adjusting the suspension travel, the drive wheels can be ensured to obtain good ground contact and sufficient grip on complex road surfaces (such as steps and ditches). At the same time, the robot body is kept stable by limiting the travel after passing through or on flat ground. This achieves the robot's good obstacle-crossing and ditch-crossing capabilities while taking into account the stability of the robot body.

[0019] 3. Simple structure, low cost, and high reliability: This utility model uses a combination of electric push rod, sliding limit component and linkage mechanism suspension to adjust the suspension stroke. Compared with the complex schemes of existing electromagnetic damping or pneumatic damping, it has fewer components and relatively simple control logic, thereby reducing manufacturing costs and improving system reliability.

[0020] 4. Excellent ride comfort and grip: The drive wheels and rear swivel wheels in the suspension assembly are linked through a four-link mechanism, which can adapt to uneven road surfaces to a certain extent and reduce bumps and vibrations. At the same time, the use of elastic elements such as tension springs can increase the downward pressure on the drive wheels, ensuring that the drive wheels have sufficient grip on the ground.

[0021] 5. Optimized wheel system layout and stability: The six-wheel, two-wheel drive differential system is relatively easy to control, has a lower cost, and the wheel system and suspension system occupy less space. At the same time, the drive wheels provide rigid support for the robot in the lateral dimension, thus achieving good longitudinal and lateral stability.

[0022] 6. Active attitude control: When the robot is about to move from a level surface to a complex road condition, or from a complex road condition back to a level surface, the travel adjustment device can proactively change the travel of the suspension components in advance through the telescopic sliding limit component, thereby achieving the effect of actively controlling the movement attitude of the mobile robot and preventing swaying or tilting caused by changes in the center of gravity or sudden stops and starts. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the chassis structure of a mobile robot chassis with an actively adjustable suspension stroke according to the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of the adjustable suspension travel mobile robot chassis according to the present invention, which limits the travel of the suspension components.

[0026] Figure 3 This is a partial cross-sectional schematic diagram of the travel adjustment device for the mobile robot chassis with actively adjustable suspension travel according to the present invention, showing the travel limit of the suspension component.

[0027] Figure 4 This is a schematic diagram of the structure of the adjustable suspension travel device for a mobile robot chassis according to the present invention, which removes the travel limitation on the suspension components.

[0028] Figure 5 This is a partial cross-sectional schematic diagram of the adjustable suspension travel device for a mobile robot chassis according to the present invention, which removes the travel restriction on the suspension components.

[0029] Figure 6 This is a schematic diagram of the sliding limit component in the stroke adjustment device of the mobile robot chassis with an actively adjustable suspension stroke according to this utility model;

[0030] Figure 7 This utility model presents a block diagram of a control method for an adjustable suspension travel mobile robot chassis, specifically a control device for adjusting the suspension travel of the mobile robot chassis.

[0031] The component names corresponding to each icon are summarized as follows: 01. Chassis frame, 02. Front caster wheel, 03. Adjustment travel device, 03-1. Electric push rod, 03-2. Sliding limit component, 03-2-1. Sliding limit component body, 03-2-2. Soft rubber buffer layer, 03-2-3. Rolling wheel, 03-3. Limit component slide groove seat, 04. Suspension assembly, 04-1. Drive wheel, 04-2. Drive wheel rocker arm, 04-3. Rear caster wheel, 04-4. Rear caster wheel rocker arm, 04-5. Linkage rod, 04-6. Suspension base, 04-7. Tension spring, 05. Tension spring hanger seat. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] Please refer to Figures 1 to 7 This utility model provides a mobile robot chassis with actively adjustable suspension travel. For example... Figure 1 As shown, the chassis adopts a six-wheel two-wheel drive differential wheel system layout. Its main structure includes a chassis frame (01), two front universal wheels (02) fixedly installed at the front of the chassis frame (01), two drive wheels (04-1) symmetrically arranged in the middle of the chassis frame (01) and driven by a motor, and two rear universal wheels (04-3) symmetrically arranged at the rear of the chassis frame (01).

[0034] Each side of the chassis is equipped with a suspension assembly (04) and a travel adjustment device (03), both of which are mounted on the chassis frame (01). The chassis body is also equipped with an inertial measurement unit (IMU), as well as sensors and an AI central control unit integrated with the robot body.

[0035] Reference Figure 1In this embodiment, each suspension assembly (04) is a four-bar linkage. Specifically, the suspension assembly (04) includes a drive wheel (04-1), a rear swivel wheel (04-3), a drive wheel rocker arm (04-2), a rear swivel wheel rocker arm (04-4), a connecting rod (04-5), a suspension base (04-6), and a tension spring (04-7). The drive wheel (04-1) is connected to one end of the drive wheel rocker arm (04-2) via its axle. The other end of the drive wheel rocker arm (04-2) is hinged to the suspension base (04-6) fixed to the chassis frame (01) via a hinge pin. Similarly, the rear swivel wheel (04-3) is connected to one end of the rear swivel wheel rocker arm (04-4) via its bracket. The other end of the rear swivel wheel rocker arm (04-4) is also hinged to the same suspension base (04-6) via a hinge pin. The two ends of the connecting rod (04-5) are connected to the middle of the drive wheel rocker arm (04-2) and the middle of the rear universal wheel rocker arm (04-4) through hinge shafts, so that the drive wheel (04-1) and the rear universal wheel (04-3) can move up and down together, thereby adapting to a certain degree of uneven road surface and reducing bumps and vibrations.

[0036] To ensure sufficient grip on the ground for the drive wheel (04-1), especially when the suspension travel is not limited, a tension spring (04-7) is connected to the drive wheel rocker arm (04-2). The other end of the tension spring (04-7) is connected to a tension spring hanger (05) fixed to the chassis frame (01). The tension spring (04-7) applies a downward pulling force to the drive wheel rocker arm (04-2), thereby increasing the normal force of the drive wheel (04-1) on the ground.

[0037] The travel adjustment device (03) is used to actively adjust the suspension travel of the suspension assembly (04). For example... Figure 1 , Figure 2 and Figure 4As shown, the stroke adjustment device (03) includes an electric push rod (03-1), a sliding limiter (03-2), and a limiter slide seat (03-3). One end of the electric push rod (03-1) (e.g., its housing end) is hinged to a specific mounting point on the chassis frame (01) via a hinge shaft, and the other end (e.g., its telescopic rod end) is hinged to the sliding limiter (03-2) via a hinge shaft. The limiter slide seat (03-3) is fixed to the chassis frame (01) and provides a guide groove for the sliding limiter (03-2). The sliding limiter (03-2) is mounted within the limiter slide seat (03-3) and is restricted to sliding in a straight line only on a plane (typically a horizontal plane). A specific surface of the sliding limiter (03-2) (e.g., its front end face) is designed to contact a specific part of the drive wheel rocker arm (04-2) (e.g., its upper surface or a contact block provided for this purpose). By extending and retracting the electric push rod (03-1), the sliding limiter (03-2) can be driven to move back and forth within the limiter slide seat (03-3), thereby changing the gap or contact state between the sliding limiter (03-2) and the drive wheel rocker arm (04-2), thus limiting the maximum stroke of the drive wheel rocker arm (04-2) relative to the chassis frame (01), which is equivalent to changing the effective stroke of the entire suspension assembly (04).

[0038] like Figure 6 The preferred structure of the sliding limiter (03-2) is illustrated below. The body (03-2-1) of the sliding limiter (03-2) is made of metal, preferably 7075 aluminum alloy, to meet structural strength requirements. Its operation involves pre-positioning the movement to create a static limit on the suspension, preventing sliding friction between it and the drive wheel rocker arm (04-2) during normal robot operation. To buffer the impact and vibration that may occur when the drive wheel rocker arm (04-2) contacts the sliding limiter (03-2) and reduce noise, a soft rubber buffer layer (03-2-2) is provided on the surface of the sliding limiter (03-2) that contacts the drive wheel rocker arm (04-2). In addition, in order to reduce the frictional resistance of the sliding limiter (03-2) when it slides in the limiter slide seat (03-3), a rolling wheel (03-2-3) can be added between the lower surface of the sliding limiter (03-2) and the contact surface of the chassis frame (01) or the limiter slide seat (03-3).

[0039] The working principle and adjustment process of this utility model are as follows: Figure 7 The control logic is as follows: Sensors on the robot body (such as LiDAR, vision sensors, ultrasonic sensors, etc.) collect environmental information in front of or around the robot in real time (such as ground flatness, obstacles, ditches, ramps, etc.). Simultaneously, an inertial measurement unit (IMU) mounted on the chassis monitors the chassis's attitude in real time, such as the tilt angle of each axis. This information is then fed back to the AI ​​central control unit.

[0040] The AI ​​central control unit analyzes and makes decisions based on the collected environmental and attitude information according to the preset application algorithm.

[0041] Scenario 1: Limiting suspension travel (e.g., entering short-travel mode / high-stiffness mode). When the robot returns to a level surface from a complex road condition (such as after crossing an obstacle), or when the sensor detects a flat ramp ahead, or when the IMU detects a significant change in the chassis's posture due to rapid acceleration, deceleration, or turning (e.g., "nodding" or tilting), the AI ​​central control unit will determine that the suspension's "stiffness" needs to be increased to maintain vehicle stability. At this time, the AI ​​central control unit sends a command signal to the electric push rod (03-1) in the travel adjustment device (03). After receiving the command, the electric push rod (03-1) extends (or retracts, depending on the specific installation method; in the example shown, it extends), pushing the sliding limit member (03-2) towards the drive wheel rocker arm (04-2) until the limiting surface of the sliding limit member (03-2) is close to or very close to the corresponding surface of the drive wheel rocker arm (04-2), such as... Figure 2 and Figure 3 As shown. This greatly reduces the upward swing space of the drive wheel rocker arm (04-2), that is, reduces the travel range of the suspension assembly (04) to a smaller set value. This is equivalent to increasing the equivalent stiffness of the suspension, thereby effectively preventing the robot from swaying due to changes in posture (such as increased center of gravity, rapid start or backward movement), and can significantly reduce the degree of backward tilting when suddenly stopping backward, thus improving stability.

[0042] Scenario 2: Releasing the suspension travel limit (e.g., entering long travel mode / flexible mode). When the robot is traveling on a level surface and needs to traverse a complex terrain (e.g., steps, ditches, or uneven ground ahead), the AI ​​central control unit determines that a larger suspension travel is required to ensure passability and the traction of the drive wheels. At this time, the AI ​​central control unit sends a command signal to the electric push rod (03-1) in the travel adjustment device (03). After receiving the command, the electric push rod (03-1) retracts (or extends, in the example shown, retracts), pulling the sliding limit piece (03-2) away from the drive wheel rocker arm (04-2), such as... Figure 4 and Figure 5 As shown. This removes the restriction on the upward swing range of the drive wheel rocker arm (04-2), allowing the drive wheel (04-1) to move downward, making better contact with the ground and maintaining sufficient grip, thus enabling the robot to climb slopes or cross ditches smoothly.

[0043] Through the above methods, the mobile robot chassis of this utility model can actively and intelligently adjust its suspension stroke according to the actual road conditions and robot operating status, realizing the switching between two levels: long stroke (flexible mode) and short stroke (high rigidity mode), so as to adapt to the needs of different working conditions such as common planar movement and crossing obstacles in the home environment.

[0044] In summary, this invention achieves active adjustment of the suspension stroke by setting a sliding limit component driven by an electric push rod to change the range of motion of the drive wheel rocker arm. This design is not only relatively simple in structure, low in cost, and highly reliable, but also significantly improves the adaptability, stability, and maneuverability of mobile robots in complex environments, effectively solving related problems existing in the prior art.

[0045] It should be noted that the directional terms such as "front," "rear," "up," "down," and "middle" described in this specification are defined based on the robot's conventional travel direction and placement as shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A mobile robot chassis with actively adjustable suspension travel, characterized in that, include: Chassis frame: At least two front wheels are fixedly mounted to the front of the chassis frame; At least two drive wheels are located in the middle of the chassis frame; At least two rear wheels are located at the rear of the chassis frame; At least two suspension assemblies are respectively mounted on the chassis frame. The suspension assemblies are movably connected to the drive wheel and the rear wheel. Each suspension assembly includes a drive wheel rocker arm, which is connected to the drive wheel. And at least one stroke adjustment device is installed on the chassis frame. The stroke adjustment device includes an electric push rod and a sliding limit member. The electric push rod is connected to the sliding limit member and drives the sliding limit member to move. The sliding limit member changes the range of motion of the drive wheel rocker arm relative to the chassis frame by cooperating with the drive wheel rocker arm.

2. The mobile robot chassis with actively adjustable suspension travel according to claim 1, characterized in that, The front wheel is a front omnidirectional wheel, and the rear wheel is a rear omnidirectional wheel; the suspension assembly also includes a rear omnidirectional wheel rocker arm connected to the rear omnidirectional wheel and a connecting rod connecting the drive wheel rocker arm and the rear omnidirectional wheel rocker arm. The drive wheel rocker arm and the rear omnidirectional wheel rocker arm are both hinged to the suspension base to form a four-bar linkage mechanism, so that the rear omnidirectional wheel is linked with the drive wheel.

3. The mobile robot chassis with actively adjustable suspension travel according to claim 1 or 2, characterized in that, The travel adjustment device further includes a limiting member slide seat, which is fixed to the chassis frame. The sliding limiting member is installed in the limiting member slide seat and slides along the straight path defined by it.

4. The mobile robot chassis with actively adjustable suspension travel according to any one of claims 1 or 2, characterized in that... The sliding limiter has a soft rubber buffer layer on the side that contacts the drive wheel rocker arm.

5. The mobile robot chassis with actively adjustable suspension travel according to claim 3, characterized in that, A rolling wheel is provided between the bottom of the sliding limiter and the chassis frame or the sliding groove seat of the limiter.

6. The mobile robot chassis with actively adjustable suspension travel according to any one of claims 1 or 2, characterized in that... The suspension assembly also includes a tension spring connected between the drive wheel rocker arm and the tension spring hanger seat fixed to the chassis frame.

7. The mobile robot chassis with actively adjustable suspension travel according to claim 1, characterized in that, The chassis is also equipped with an inertial measurement unit and sensors, and the robot body is equipped with an AI central control unit.

8. The mobile robot chassis with actively adjustable suspension travel according to claim 1, characterized in that, The body of the sliding limiter is made of aluminum alloy.

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