Long-endurance exoskeleton device and method

Abstract

The invention discloses a long-endurance exoskeleton device and method, and relates to the technical field of exoskeletons.The long-endurance exoskeleton device comprises a waist part, leg parts and a controller, and a fuel cell and a lithium battery are installed on the waist part; the leg parts are connected to the lower side of the waist part, one leg part is provided with a fuel container, and the other leg part is provided with a gas container; the leg part is further provided with a strain sensor and a rotary encoder, the strain sensor is used for acquiring force applied to the knee joint, and the rotary encoder is used for detecting the angle of the knee joint; the controller is used for calculating power according to the force applied to the knee joint and the angle at the knee joint and switching the lithium battery or the fuel battery to supply power according to the power. The hybrid power supply mode of the lithium battery and the fuel battery is adopted, the corresponding working mode is set, the longer endurance time can be achieved, and the requirements of plateau areas and the like are met.

Description

Technical Field

[0001] The present invention relates to the technical field of exoskeleton, and in particular to a long-endurance exoskeleton device and method. Background Art

[0002] For high altitude or mountainous areas, people usually wear exoskeleton devices to carry equipment or supplies, but the current exoskeleton devices have problems such as insufficient endurance, resulting in poor adaptability in the above areas. Although there are some hybrid power methods in the prior art, there are still some problems, such as:

[0003] Chinese invention patent CN117428742A discloses a hybrid exoskeleton for battlefield rescue, including a load-bearing associated bracket, an energy supply control box and a joint bearing member. By adopting a hybrid power system, mechanical power and battery power are combined. Mechanical power can be generated by the athlete's actions, while the battery provides a stable power supply to ensure the continuous operation of the equipment. Although this solution is a hybrid power, it is actually a combination of mechanical power and battery. The power supply battery is still powered by a single battery, which cannot meet the long-term endurance requirements.

[0004] Chinese invention patent CN113370967A discloses a remotely controlled intelligent car and method based on a hybrid power system. The car body is equipped with a hydrogen fuel cell module and an additional control circuit module, a lithium battery and a charging and discharging circuit module, etc. Based on the intelligent control of the hydrogen battery and the lithium battery, the hydrogen fuel cell and the lithium battery can remotely control the driving part of the car. Since the power demand of the car is relatively stable and the car usually does not require a very fast response, the lithium battery and fuel cell switching method disclosed in this scheme is not suitable for exoskeleton devices. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a long-endurance exoskeleton device and method, which adopts a hybrid power supply method of lithium batteries and fuel cells and sets corresponding working modes, so as to achieve longer endurance time and meet the requirements of plateau areas.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a long-endurance exoskeleton device, comprising:

[0008] The waist, on which the fuel cell and lithium battery are mounted;

[0009] A leg part connected to the lower side of the waist, wherein a fuel container is installed on one leg part and a gas container is installed on the other leg part; a strain sensor and a rotary encoder are also installed on the leg part, wherein the strain sensor is used to obtain the force applied to the knee joint, and the rotary encoder is used to detect the angle at the knee joint;

[0010] The controller is used to calculate the power according to the force applied to the knee joint and the angle at the knee joint, and switch the lithium battery or fuel cell to supply power according to the power.

[0011] As a further implementation, the bottom end of the leg is connected to the foot, and the foot is equipped with a pressure sensor, which is used to detect the pressure applied to the contact surface of the exoskeleton.

[0012] As a further implementation, a hydrogen sensor is also installed on the waist, and the hydrogen sensor is used to detect the hydrogen concentration of the fuel cell;

[0013] The hydrogen sensor is connected to a controller, and the controller can switch to a lithium battery for power supply when the hydrogen concentration is abnormal.

[0014] As a further implementation, the waist is installed with a back support structure, and the back support structure includes a backrest body and a tray connected to the backrest body.

[0015] As a further implementation, the backrest body is made of carbon fiber material, and the tray is made of titanium alloy material.

[0016] In a second aspect, an embodiment of the present invention further provides a control method for a long-endurance exoskeleton device, comprising:

[0017] The lithium battery supplies power to the exoskeleton device when started;

[0018] Acquire foot pressure information, knee joint strain information and angle information in real time, and calculate power according to the knee joint strain information and angle information;

[0019] It is determined whether the power is within a preset threshold value, and when the power exceeds the threshold value, the power supply is switched to the fuel cell.

[0020] As a further implementation, the threshold is within the range of 200 to 300W.

[0021] As a further implementation, the power is calculated as follows:

[0022] P = τ × ω;

[0023] Among them, τ represents torque; ω represents angular velocity, which is obtained by a rotary encoder;

[0024] τ=F×r×cosθ;

[0025] F represents the force applied to the knee joint, which is obtained by the strain sensor; r represents the rotation radius of the knee joint, and θ represents the angle between the force and the lever arm.

[0026] As a further implementation, the load borne by the foot is calculated based on the foot pressure information:

[0027] F GRF =P 压强 ×A;

[0028] Among them, P 压强 is the pressure measured by the pressure sensor, A represents the contact area of ​​the sensor, and F GRF Represents the ground reaction force.

[0029] As a further implementation, the exoskeleton device switches to lithium battery power supply when it stops.

[0030] The beneficial effects of the present invention are as follows:

[0031] (1) The exoskeleton device of the present invention is equipped with a lithium battery and a fuel cell, and is also provided with a strain sensor, a pressure sensor, and a rotary encoder. The strain sensor is used to obtain the force applied to the knee joint, and the rotary encoder is used to detect the angle change of the knee joint and calculate the angular velocity based on the angle change. Power is obtained based on the strain and angle, and the power is used as an indicator to achieve the switching between the lithium battery and the fuel cell, thereby ensuring the long battery life of the exoskeleton device. At the same time, a pressure sensor is also provided. The pressure sensor is used to measure the pressure on the contact surface of the exoskeleton, and the gait change and load change information are obtained by monitoring the pressure of the contact between the foot and the ground.

[0032] (2) The present invention distributes lithium batteries and fuel cell components in different parts of the exoskeleton through modular design, thereby balancing the load and reducing the weight of a single part; and a back support structure is installed at the waist, which is used to bear the heavy objects carried by the wearer, thereby reducing the wearer's physical burden and enhancing his adaptability in harsh environments such as plateaus. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0034] Figure 1 is a schematic structural diagram of a long-endurance exoskeleton device according to one or more embodiments of the present invention;

[0035] Figure 2 is a control flow chart of a long-endurance exoskeleton device according to one or more embodiments of the present invention.

[0036] Among them, 1. shoulder strap, 2. back support structure, 3. waist, 4. legs, 5. feet, 6. lithium battery, 7. fuel cell, 8. strain sensor, 9. pressure sensor, 10. rotary encoder, 11. hydrogen sensor, 12. fuel container, 13. gas container, 14. knee joint. DETAILED DESCRIPTION

[0037] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0038] Embodiment 1:

[0039] This embodiment provides a long-endurance exoskeleton device, which is driven by a lithium battery 6 and a fuel cell 7, and can meet the long-endurance requirements of plateau environments. The lithium battery 6 and the fuel cell 7 components are distributed in different parts of the exoskeleton through modular design, so as to balance the load and reduce the weight of a single part. Figure 1 As shown, the exoskeleton device includes a waist 3, legs 4, and feet 5. The lower side of the waist 3 is connected to two legs 4, and the bottom ends of the legs 4 are connected to the feet 5. The upper side of the waist 3 is also connected to a strap 1 for wearing the exoskeleton device on the back.

[0040] The fuel cell 7 and the lithium battery 6 are both installed on the waist 3, and the fuel cell 7 is located in the middle of the waist 3, and the lithium battery 6 is located on one side of the fuel cell 7; the fuel cell 7 is equipped with a fuel container 12 and a gas container 13, wherein the fuel container 12 is used to provide liquid fuel to the combustion chamber of the fuel cell 7, and the gas container 13 is used to provide oxygen to the combustion chamber. In order to achieve the purpose of balanced load, the fuel container 12 of this embodiment is installed on one of the legs 4, and the gas container 13 is installed on the other leg 4, and the fuel container 12 and the gas container 13 are both located above the knee joint 14.

[0041] The back support structure 2 is installed on the upper side of the waist 3. The back support structure 2 is used to carry the heavy objects carried by the wearer, thereby reducing the physical burden of the wearer and enhancing his adaptability in harsh environments such as plateaus. The back support structure 2 of this embodiment includes a backrest body and a tray. The tray is fixedly connected to the backrest body and is used to carry heavy objects. The tray is made of titanium alloy material. Under the conditions of low temperature, low humidity and strong ultraviolet rays in the plateau environment, the titanium alloy can maintain long-term stability. The backrest body is made of carbon fiber material, which has high strength and lightweight characteristics. It can reduce additional weight while ensuring firmness, and is particularly suitable for long-term wear.

[0042] In addition, in this embodiment, a silicone sealing strip is provided at the knee joint 14, which can effectively prevent the entry of sand and dust. At the same time, dust covers are designed at the sockets and interfaces. When the interfaces are not in use, the dust covers can effectively prevent the entry of sand and dust, thereby ensuring the normal operation of the exoskeleton device.

[0043] like Figure 1 As shown, a rotary encoder 10 and a strain sensor 8 are installed at the knee joint 14 of the exoskeleton device. The strain sensor 8 is used to obtain the force applied to the knee joint 14, and the rotary encoder 10 is used to detect the angle change of the knee joint 14 and calculate the angular velocity based on the angle change. The foot 5 is installed with a pressure sensor 9 for measuring the pressure of the contact surface of the exoskeleton, and the gait change and load change information are obtained by calculating the pressure of the foot 5 in contact with the ground. The waist 3 is also installed with a hydrogen sensor 11 for detecting the hydrogen concentration of the fuel cell 7 to ensure that the hydrogen is switched to the lithium battery 6 when the hydrogen leaks or the concentration is too high, thereby ensuring the safety of the exoskeleton device.

[0044] This embodiment also provides a DSP digital signal processor and a controller, wherein the controller is embedded near the power module of the waist 3; the waist 3 is a hub connecting the upper and lower limbs, and the signal line and the power line can be quickly transmitted from the waist 3 to the limb modules, which is convenient for connection and wiring; and the position of the waist 3 is stable, which can reduce the influence of the controller on the soldier's strenuous movement (such as running and jumping), and has good stability; the position of the waist 3 is convenient for the soldier to quickly contact the controller or its interface when needed, and has high operability.

[0045] like Figure 2 As shown, the DSP digital signal processor analyzes the strain and angle according to the strain sensor 8 and the rotary encoder 10, and transmits them to the controller, which determines the motion mode and calculates the current power demand. According to the pre-set power threshold range, when the threshold range is exceeded, the fuel cell 7 is switched to power supply, and the lithium battery 6 is used for power supply within the threshold range, so as to achieve long battery life.

[0046] Since lithium battery 6 has the advantages of high energy density, fast startup speed, and good low temperature performance, it is very suitable for the start-stop stage of the exoskeleton; during the startup stage, lithium battery 6 can quickly provide the required energy for the exoskeleton to quickly enter the working state. Hydrogen fuel cells have the advantages of high efficiency, cleanliness, economy, and safety, and have a long battery life. During the normal walking stage, hydrogen fuel cells can provide stable energy output for the exoskeleton. In addition, the byproduct of the hydrogen fuel cell reaction is water, which is environmentally friendly.

[0047] Therefore, the exoskeleton device of this embodiment adopts a hybrid power supply method of lithium battery 6 and fuel cell 7. Lithium battery 6 is used for power supply during start and stop. When working, power is used as a judgment indicator to switch between fuel cell 7 power supply and lithium battery 6 power supply, which can achieve efficient energy utilization and longer battery life.

[0048] Embodiment 2:

[0049] This embodiment provides a control method for a long-life exoskeleton device, using the exoskeleton device described in Example 1, such as Figure 2 As shown, when starting, the lithium battery 6 is used to power the exoskeleton device; the pressure information of the foot 5, the strain information and the angle information of the knee joint 14 are obtained in real time, and the power is calculated according to the strain information and the angle information of the knee joint 14; it is determined whether the power is within a preset threshold, and when the threshold is exceeded, it is switched to the fuel cell 7 for power supply.

[0050] This embodiment takes the military exoskeleton scenario in a plateau environment as an example to explain in detail:

[0051] Specifically, the following steps are included:

[0052] S1: Preparation, soldiers put on exoskeleton devices.

[0053] S2: Start the exoskeleton lithium battery 6 to power the soldier, and the soldier begins to perform daily tasks such as patrolling. The foot 5 pressure sensor 9 monitors the pressure changes of the soldier's foot 5 when walking to evaluate the load size; at the same time, the knee joint 14 strain sensor 8 and the rotary encoder 10 respectively measure the strain and detect the angle change, and transmit the collected data to the DSP digital signal processor, which performs real-time signal processing. The signal processed by the DSP digital signal processor can be transmitted to the controller through different communication protocols (such as SPI, I2C, UART, CAN, etc.), and the controller analyzes the soldier's movement mode (normal walking, running, climbing, weight-bearing walking, etc.) and calculates the current power demand.

[0054] The power threshold of this embodiment is adaptively selected within the range of 200 to 300W. Taking the threshold of 200W as an example, when the power demand exceeds the threshold of 200W, the controller will send the generated switching signal to the BMS battery management system through the CAN bus communication interface. The BMS battery management system cuts off the connection between the lithium battery 6 and the exoskeleton load through the control signal to stop power supply. Then the BMS battery management system controls the MOSFET switch switching circuit to connect to the fuel cell 7 to provide power for the exoskeleton.

[0055] During the power supply by the fuel cell 7 , the hydrogen sensor 11 installed on the waist 3 monitors the hydrogen concentration in real time, and switches to the lithium battery 6 for power supply when hydrogen leaks or the concentration is too high.

[0056] When the power demand tends to decrease and drops below the threshold value of 200 W, the lithium battery 6 is switched to supply power.

[0057] This cycle works in reverse to achieve more efficient energy utilization and longer battery life, ensuring that soldiers can continue to perform their missions.

[0058] Furthermore, by measuring the pressure on the contact surface of the exoskeleton, the load borne by each foot 5 is calculated. This load directly affects the driving power of the motor in the design of the exoskeleton.

[0059] F GRF =P 压强 ×A (1)

[0060] In formula (1), P 压强 is the pressure measured by the pressure sensor (unit: Pa), A represents the sensor contact area (unit: m 2 ), F GRF Represents the ground reaction force (unit: N).

[0061] The pressure sensor 9 can detect the pressure applied to the ground by soldiers during walking, running, jumping and other movements. These data are crucial for the regulation of the exoskeleton device, which is specifically manifested in real-time adjustment of the exoskeleton's movements and power requirements to optimize the device's performance and reduce energy waste.

[0062] (1) Gait optimization:

[0063] Pressure distribution analysis: Through the pressure sensor 9, the exoskeleton device can detect the pressure distribution and gait changes of each step. For example, by detecting the difference in the ground pressure between the heel and the forefoot, the device can adjust the motor output and joint activity according to the type of gait (such as walking, running or climbing) to more naturally match the soldier's movement.

[0064] Shock absorption function: When the pressure sensor 9 detects a large pressure (such as the impact force generated when running or jumping), the exoskeleton can adjust the flexibility of the joints or increase the buffer to reduce the impact of the impact force on the soldier's body. In this way, the exoskeleton not only helps the soldier reduce the burden, but also reduces the fatigue caused by the burden.

[0065] (2) Real-time power demand adjustment:

[0066] Adjusting power output according to load: The power system of the exoskeleton device (such as an electric motor or hydraulic system) determines the size of the load currently applied by the soldier based on the data from the pressure sensor 9. For example, if the pressure sensor 9 detects an increase in weight (such as walking or jumping with a weight), the exoskeleton can increase power output, provide more auxiliary force, and reduce the burden on the soldier.

[0067] Energy-saving control: When the pressure sensor 9 detects that the soldier is in a low-load state (such as walking on flat ground or resting), the exoskeleton can reduce power output accordingly to reduce energy consumption. This dynamic power regulation helps to extend the working time of the exoskeleton and improve the energy efficiency of the overall system. Reducing power output here means to optimize energy saving as much as possible within the threshold range.

[0068] Furthermore, when the exoskeleton performs movements, the work of the drive motors usually depends on the torque of the joints; in order to infer the power requirements, it is first necessary to infer the torque of the joints by measuring the force, as follows:

[0069] τ=F×r×cosθ (2)

[0070] In formula (2), F represents the force applied to the knee joint (unit: N), which is calculated based on the strain measured by the strain sensor; r is the length of the lever arm, that is, the rotation radius of the knee joint (unit: m), and θ represents the angle between the force and the lever arm (usually 0° or 90°).

[0071] P=τ×ω (3)

[0072] In formula (3), P represents power (unit: W), τ represents torque (unit: N·m), and ω represents angular velocity (unit: rad / s), which is obtained by a rotary encoder.

[0073] The calculation process of F is:

[0074] F=k·ΔR (4)

[0075] In formula (4), k is a constant, which is usually related to the installation and calibration of the strain sensor; ΔR is the measured resistance change, as follows:

[0076] ΔR=R0·G·ε (5)

[0077] In formula (5), R0 is the original resistance of the strain sensor, G is the sensitivity coefficient of the strain sensor (also called strain sensitivity factor), and ε is the strain, which is measured by the strain sensor.

[0078] Furthermore, the rotary encoder can calculate the angular velocity by monitoring the angle change of the knee joint in real time. The basic principle is to measure the angle through the rotary encoder, and then calculate the rate of change of the angle over time to obtain the angular velocity:

[0079]

[0080] In formula (6), ω(t) is the angular velocity in the time interval [t1, t2], and the unit is usually degrees per second (° / s) or radians per second (rad / s); Δθ=θ2-θ1 is the change in angle (angle difference); Δt=t2-t1 is the time interval, and the unit is seconds (s).

[0081] Since power (especially the power demand per unit time) is closely related to the energy consumption of the exoskeleton system, the battery power supply of the exoskeleton system is directly linked to the power demand. By monitoring the power, the system can evaluate the energy demand of the exoskeleton in real time, and then effectively manage the switching of the battery and the power supply mode. Indicators such as acceleration and position change can only indirectly reflect the movement state of the soldier, but cannot be directly mapped to the power demand of the system. Therefore, this embodiment uses power as a direct physical quantity, which can more accurately reflect the actual energy consumption.

[0082] According to the plateau application scenarios of the exoskeleton, the power demand is usually between 50W and 500W, and 200-300W is a reasonable compromise range that can cover the actual needs in most cases. Therefore, the power threshold can be set within the range of 200-300W, and the specific value can be determined according to the actual needs of the exoskeleton device. In addition, the choice of 200-300W helps to achieve the best switch between lithium batteries and fuel cells. Lithium batteries have higher energy efficiency and longer use time under low power loads (such as 50-200W). Using lithium batteries at low power requirements can extend battery life, and the cost of lithium batteries is low, which is suitable for daily or low-load scenarios; fuel cells can provide power more efficiently under high power requirements (such as more than 200W), and can last longer, which is suitable for use in weight-bearing walking or rugged terrain. When the power demand of the exoskeleton exceeds the pre-set power threshold, switching to fuel cells can avoid the battery life being shortened due to excessive consumption of lithium batteries.

[0083] If the threshold is set too low (e.g. 100W), the lithium battery may reach its load limit too early in more complex tasks (such as uphill or loaded walking), resulting in frequent battery switching, increasing system complexity and risk of failure. If the threshold is set too high (e.g. above 300W), the fuel cell may be frequently enabled, which will increase the cost and weight of the system and is not conducive to long-term use. Therefore, selecting a threshold within the range of 200 to 300W can reduce the number of switching times and optimize the efficiency of battery use.

[0084] In summary, this embodiment uses 200-300W as the threshold range, which can not only ensure that the power requirements of the exoskeleton system in most working environments are met, but also avoid over-reliance on fuel cells, thereby reducing costs and system weight; achieving more efficient energy use and longer battery life.

[0085] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A long-endurance exoskeleton device, characterized in that: include: The waist, on which the fuel cell and lithium battery are mounted; A leg part connected to the lower side of the waist, wherein a fuel container is installed on one leg part and a gas container is installed on the other leg part; a strain sensor and a rotary encoder are also installed on the leg part, wherein the strain sensor is used to obtain the force applied to the knee joint, and the rotary encoder is used to detect the angle at the knee joint; The controller is used to calculate the power according to the force applied to the knee joint and the angle at the knee joint, and switch the lithium battery or fuel cell to supply power according to the power.

2. A long-endurance exoskeleton device according to claim 1, characterized in that: The bottom end of the leg is connected to the foot, and the foot is equipped with a pressure sensor, which is used to detect the pressure applied to the contact surface of the exoskeleton.

3. The long-endurance exoskeleton device according to claim 1, characterized in that: The waist is also equipped with a hydrogen sensor, which is used to detect the hydrogen concentration of the fuel cell; The hydrogen sensor is connected to a controller, and the controller can switch to a lithium battery for power supply when the hydrogen concentration is abnormal.

4. A long-endurance exoskeleton device according to claim 1 or 3, characterized in that: The waist is equipped with a back support structure, which includes a backrest body and a tray connected to the backrest body.

5. The long-endurance exoskeleton device according to claim 4, characterized in that: The backrest body is made of carbon fiber material, and the tray is made of titanium alloy material.

6. A control method for a long-endurance exoskeleton device according to any one of claims 1 to 5, characterized in that: include: The lithium battery supplies power to the exoskeleton device when started; Acquire foot pressure information, knee joint strain information and angle information in real time, and calculate power according to the knee joint strain information and angle information; It is determined whether the power is within a preset threshold value, and when the power exceeds the threshold value, the power supply is switched to the fuel cell.

7. The control method of a long-endurance exoskeleton device according to claim 6, characterized in that: The threshold is within the range of 200 to 300W.

8. The control method of a long-endurance exoskeleton device according to claim 6, characterized in that: The power is calculated as: P = τ × ω; Among them, τ represents torque; ω represents angular velocity, which is obtained by a rotary encoder; τ=F×r×cosθ; F represents the force applied to the knee joint, which is obtained by the strain sensor; r represents the rotation radius of the knee joint, and θ represents the angle between the force and the lever arm.

9. The control method of a long-endurance exoskeleton device according to claim 6, characterized in that: Calculate the load on your foot based on the foot pressure information: F GRF =P 压强 ×A; Among them, P 压强 is the pressure measured by the pressure sensor, A represents the contact area of ​​the sensor, and F GRF Represents the ground reaction force.

10. The control method of a long-endurance exoskeleton device according to claim 6, characterized in that: When the exoskeleton device stops, it switches to lithium battery power supply.

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