Intelligent furniture anti-pinch control method

Abstract

The invention discloses an intelligent furniture anti-pinch control method, and particularly relates to the technical field of intelligent furniture, an intelligent furniture overall frame composed of all movable modules is driven through a push rod, so that stretching and folding actions of the intelligent furniture are completed, pressure sensors are arranged at all the movable modules of the intelligent furniture, and the intelligent furniture anti-pinch control method is achieved. Acquiring a pressure value of each activity module of the intelligent furniture; a current sensor is arranged on a power supply or a manual operator of the intelligent furniture to obtain the current current of a motor; a position detection sensor is arranged in the push rod to obtain the mechanical angular displacement of the motor or the stroke of the push rod; the total load torque of the push rod in the stretching and folding process of the intelligent furniture is obtained according to the load torque applied to the push rod by each movable module of the current intelligent furniture; and calculating a normal current value of the motor according to the obtained total load torque and the mechanical angular displacement of the motor, comparing the current current value of the motor with the calculated normal current value of the motor, and judging whether a person or an object is clamped according to an error.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent furniture, and in particular to an anti-pinch control method for intelligent furniture. Background Art

[0002] With technological advancements, products such as electric sofas, electric recliners, and smart mattresses are constantly emerging. These devices are all driven by actuators to expand, contract, and fold. Most electric sofas, electric recliners, and smart mattresses on the market lack anti-pinch features, which can cause serious consequences, even life-threatening, if they do occur. Therefore, it is essential that these actuator-driven smart furniture, such as electric sofas, electric recliners, and smart mattresses (collectively referred to as smart furniture), have anti-pinch features.

[0003] The current status of the relevant existing technologies is as follows:

[0004] (1) Using infrared sensing to detect intrusion or using the Internet of Things to detect intrusion by foreign objects has a high false detection rate. The characteristics of infrared sensing technology or the detection sensor of the Internet of Things determine that there is a certain false detection rate, and it is impossible to determine whether the intruding object is clamped.

[0005] (2) Add thin film pressure sensors to the extrusion parts of the moving parts of smart furniture to detect whether there is an object intrusion. Because smart furniture has many moving parts and many installation locations, thin film pressure sensors are difficult to install. In addition, the sensors move with the moving parts of smart furniture, which has the disadvantages of easy damage to the cables and short lifespan.

[0006] (3) Use millimeter-wave radar to monitor the area of ​​​​moving parts for the presence of micro-animal targets. Millimeter-wave radar is expensive and requires high installation precision. There are many types of micro-animals, and the area of ​​​​moving parts of smart furniture is complex. Therefore, the algorithm is difficult and the false detection rate is high.

[0007] (4) By installing a multi-channel capacitive sensing plate at the end of the telescopic iron frame of the electric smart furniture to detect whether there is an object intrusion. This technology can only detect whether there is a foreign object intrusion at the end position of the smart furniture. If the foreign object is at a non-end position, it cannot be effectively detected.

[0008] (5) Detecting whether an object has intruded by collecting the motor current data of electric smart furniture. When an object intrudes, the motor current and speed will inevitably change simultaneously. Theoretically, detecting only the current will result in a false positive rate. Furthermore, the body shapes and weights of smart furniture occupants vary greatly. During the movement of smart furniture, the current waveform data varies greatly. There is no universal or finite number of thresholds, resulting in a high false positive rate.

[0009] (6) DC motor anti-pinch method through current pulse detection. Current pulse detection is essentially a rotation detection of the motor, that is, it detects the change in motor speed. Ignoring the motor current amplitude and only observing the change in motor speed will inevitably lead to false detection. In addition, the motor has a large moment of inertia. In the early stage of foreign object intrusion, the speed change is very small, and the detection accuracy is not high. Summary of the Invention

[0010] To this end, the present invention provides an anti-pinch control method for intelligent furniture to solve the problems raised in the background technology.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a method for controlling anti-pinch in intelligent furniture, wherein a push rod drives an overall intelligent furniture frame composed of various movable modules, thereby completing the expansion and contraction of the intelligent furniture, comprising the following steps:

[0012] Step 1: Set up pressure sensors at each active module of the smart furniture to obtain the pressure value g of each active module of the smart furniture x By setting a current sensor in the power supply or handheld controller of the smart furniture, the current current of the motor can be obtained; by setting a position detection sensor inside the push rod, the mechanical angular displacement θ of the motor or the push rod stroke can be obtained;

[0013] Step 2: The load torque applied by each active module of the smart furniture to the push rod;

[0014] Step 3: Based on step 2, the total load torque of the push rod during the extension and retraction of the smart furniture is obtained;

[0015] Step 4: Calculate the normal motor current value based on the obtained total load torque and motor mechanical angular displacement. Compare the current motor current value with the calculated normal motor current value. Based on the error, determine whether a person or object is trapped. If a person or object is trapped, enable the anti-pinch function.

[0016] Preferably, the movable modules of the overall frame of the intelligent furniture are hingedly connected via connecting rods or slide rails.

[0017] Preferably, the electromagnetic torque output by the push rod at any time should be equal to the total load torque of the frame and the torque increment caused by the speed change, that is, it satisfies the basic motion equation:

[0018]

[0019] Where J is the mechanical moment of inertia of the motor. Once the motor of the push rod is determined, this coefficient remains unchanged. m is the mechanical angular velocity of the motor, which is calculated by the mechanical angular displacement θ of the motor or the change in the push rod stroke; T e is the electromagnetic torque, T L is the load torque;

[0020] When the push rod is a DC motor, the electromagnetic torque of the push rod is related to the torque coefficient and motor current of the motor, that is:

[0021] T e =K e I d (2)

[0022] Among them, K e is the torque coefficient of the motor, which is related to the motor structure. Once the motor is determined, the coefficient remains unchanged; I d is the load current; the electromagnetic torque output by the motor is proportional to the DC motor current;

[0023] Combining equations (1) and (2), we get the load current I d :

[0024]

[0025] Preferably, assuming that the detection data of the pressure sensor group composed of the pressure sensors of each active module are g x (x=1,2..,n), then the load torque T applied by each active module of the current intelligent furniture to the push rod is obtained Lx , T Lx Expressed as:

[0026] T Lx =k x1 *(g x +△g x )+k x2 *(g x +△g x ) 2 +△T Lx (4)

[0027] Among them, g x Indicates the pressure sensor data corresponding to each active module, △g x Indicates the pressure caused by the weight of each active module, k x1 k represents the first-order influence coefficient of the unit pressure of each active module on the push rod load torque, x2 Indicates the second-order influence coefficient of the unit pressure of each active module on the push rod load torque, △T Lx Indicates the load torque increment caused by friction of each active module;

[0028] During the operation of the push rod, the total weight of the passengers remains unchanged, but the extension or contraction of the smart furniture will affect the pressure sensor value. Therefore, during the extension or contraction of the smart furniture, g x Changes in real time and is related to the stroke of the push rod.

[0029] Preferably, the first-order and second-order influence coefficients k of the load torque of the push rod per unit pressure are x1 、k x2 The change of each operating state during the stretching process of the smart furniture leads to k x1 、k x2 With the stroke of the push rod, k x1 、k x2 is a piecewise constant related to the push rod stroke. This coefficient changes with the structure of the smart furniture. There is no universal quantitative formula, but the smart furniture frame is fixed. This coefficient is a fixed value and is related to the segment. The push rod stroke is linearly related to the mechanical angular displacement θ of the motor, so k x1 、k x2 The mechanical angular displacement θ of the motor changes in stages, that is:

[0030] k x1 =f 1x (θ)

[0031] k x2 =f 2x (θ) (5)

[0032] Therefore, the load torque T of each active module of the smart furniture on the push rod Lx As the push rod stroke and the motor's mechanical angular displacement θ change, during the operation of smart furniture, the load torque T of each active module on the push rod Lx The mechanical angular displacement θ of the motor or the stroke of the push rod, and the pressure sensor data g x Related:

[0033] T Lx =f(g x ,θ) (6)

[0034] During the operation of smart furniture, the total load torque of the push rod is expressed as the sum of the load torques of each active module, that is:

[0035]

[0036] Therefore, the total load torque is related to the motor's mechanical angular displacement θ or the push rod stroke and the pressure sensor data g x Related; During the operation of the push rod, the pressure sensor data of each active module is detected g x Substitute the motor mechanical angular displacement θ or the push rod stroke into equations (4) and (7) to obtain the push rod load torque;

[0037] The push rod load torque T L Enter the above formula (3) to get the calculated load current I of the motor d .

[0038] Preferably, the real-time current i of the motor is collected and compared with the calculated load current I d Do a comparison, if the difference between the two exceeds the threshold △I d , it is determined that there is foreign object intrusion, that is, there is a situation of clamping objects or people, the controller sends an alarm signal, and stops the push rod from running or controls the push rod to run in the opposite direction for a distance.

[0039] The present invention has the following advantages:

[0040] The overall frame of the smart furniture composed of various active modules is driven by a push rod to complete the stretching and retracting actions of the smart furniture. By arranging a pressure sensor at each active module of the smart furniture, the pressure value of each active module of the smart furniture is obtained; by arranging a current sensor at the power supply or hand controller of the smart furniture, the current current of the motor is obtained; by arranging a position detection sensor inside the push rod, the mechanical angular displacement of the motor or the push rod stroke is obtained; the load torque applied to the push rod by each active module of the current smart furniture is obtained, and the total load torque of the push rod during the stretching and retracting of the smart furniture is obtained; based on the obtained total load torque and the mechanical angular displacement of the motor, the normal current value of the motor is calculated, and the current current value of the motor is compared with the calculated normal current value of the motor. It is judged whether a person or object is clamped based on the error. Compared with the prior art, the pressure sensor added by the present invention is at a supporting position such as a seat or leg, the sensor cable is easy to install, and the movement has little effect on the sensor cable, and the effect on the cable life is very small. The present invention adds a pressure sensor to ensure the consistency of current data under different weights and body shapes of passengers. The present invention also detects the mechanical angular displacement of the motor to ensure the consistency of current data under different strokes of the push rod. The mechanical rotational inertia, the torque coefficient of the motor and the piecewise constants corresponding to different strokes relied on by the present invention are guaranteed to have data consistency by the machining precision. Therefore, the present invention can effectively detect whether there is a person or object being pinched. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 A schematic diagram of the overall structure of the anti-pinch smart sofa provided by an embodiment of the present invention;

[0042] Figure 2 This is a flow chart of the anti-pinch control method for a smart sofa provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The following describes the implementation of the present invention using specific embodiments. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. Obviously, the embodiments described are only a portion of the present invention, not all of it. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are intended to fall within the scope of protection of the present invention.

[0044] The present invention provides an anti-pinch control method for smart furniture, which drives the overall frame of the smart furniture composed of various movable modules by a push rod, thereby completing the stretching and retracting actions of the smart furniture, including the following steps:

[0045] Step 1: Set up pressure sensors at each active module of the smart furniture to obtain the pressure value g of each active module of the smart furniture x By setting a current sensor in the power supply or handheld controller of the smart furniture, the current current of the motor can be obtained; by setting a position detection sensor inside the push rod, the mechanical angular displacement θ of the motor or the push rod stroke can be obtained;

[0046] The positions of all moving parts of the smart home can be set, or only some key positions can be set. For example, only the seats can be set, and the overall load can be calculated based on the parameters.

[0047] Step 2: The load torque applied by each active module of the smart furniture to the push rod;

[0048] Step 3: Based on step 2, the total load torque of the push rod during the extension and retraction of the smart furniture is obtained;

[0049] Step 4: Calculate the normal motor current value based on the obtained total load torque and motor mechanical angular displacement. Compare the current motor current value with the calculated normal motor current value. Based on the error, determine whether a person or object is trapped. If a person or object is trapped, enable the anti-pinch function.

[0050] The movable modules of the overall frame of the intelligent furniture are hingedly connected by connecting rods or slide rails.

[0051] The electromagnetic torque output by the push rod at any time should be equal to the total load torque of the frame and the torque increment caused by the speed change, that is, it satisfies the basic motion equation:

[0052]

[0053] Where J is the mechanical moment of inertia of the motor. Once the motor of the push rod is determined, this coefficient remains unchanged; ω m is the mechanical angular velocity of the motor, which is calculated by the mechanical angular displacement θ of the motor or the change in the push rod stroke; T e is the electromagnetic torque, T L is the load torque;

[0054] When the push rod is a DC motor, the electromagnetic torque of the push rod is related to the torque coefficient and motor current of the motor, that is:

[0055] T e =K e I d (2)

[0056] Among them, K e is the torque coefficient of the motor, which is related to the motor structure. Once the motor is determined, the coefficient remains unchanged; I d is the load current; the electromagnetic torque output by the motor is proportional to the DC motor current;

[0057] Combining equations (1) and (2), we get the load current I d :

[0058]

[0059] Preferably, assuming that the detection data of the pressure sensor group composed of the pressure sensors of each active module are g x (x=1,2..,n), then the load torque T applied by each active module of the current intelligent furniture to the push rod is obtained Lx , T Lx Expressed as:

[0060] T Lx =k x1 *(g x +△g x )+k x2 *(g x +△g x ) 2 +△T Lx (4)

[0061] Among them, g x Indicates the pressure sensor data corresponding to each active module, △g x Indicates the pressure caused by the weight of each active module, k x1 k represents the first-order influence coefficient of the unit pressure of each active module on the push rod load torque, x2 Indicates the second-order influence coefficient of the unit pressure of each active module on the push rod load torque, △T Lx Indicates the load torque increment caused by friction of each active module;

[0062] During the operation of the push rod, the total weight of the passengers remains unchanged, but the extension or contraction of the smart furniture will affect the pressure sensor value. Therefore, during the extension or contraction of the smart furniture, g x Changes in real time and is related to the stroke of the push rod.

[0063] The first-order and second-order influence coefficients k of unit pressure on the load torque of the push rod x1 、k x2 The change of each operating state during the stretching process of the smart furniture leads to k x1 、k x2 With the stroke of the push rod, k x1 、k x2is a piecewise constant related to the push rod stroke. This coefficient changes with the structure of the smart furniture. There is no universal quantitative formula, but the smart furniture frame is fixed. This coefficient is a fixed value and is related to the segment. The push rod stroke is linearly related to the mechanical angular displacement θ of the motor, so k x1 、k x2 The mechanical angular displacement θ of the motor changes in stages, that is:

[0064] k x1 =f 1x (θ)

[0065] k x2 =f 2x (θ) (5)

[0066] Therefore, the load torque T of each active module of the smart furniture on the push rod Lx As the push rod stroke and the motor's mechanical angular displacement θ change, during the operation of smart furniture, the load torque T of each active module on the push rod Lx The mechanical angular displacement θ of the motor or the stroke of the push rod, and the pressure sensor data g x Related:

[0067] T Lx =f(g x ,θ) (6)

[0068] During the operation of smart furniture, the total load torque of the push rod is expressed as the sum of the load torques of each active module, that is:

[0069]

[0070] Therefore, the total load torque is related to the motor's mechanical angular displacement θ or the push rod stroke and the pressure sensor data g x Related; During the operation of the push rod, the pressure sensor data of each active module is detected g x Substitute the motor mechanical angular displacement θ or the push rod stroke into equations (4) and (7) to obtain the push rod load torque;

[0071] The push rod load torque T L Enter the above formula (3) to get the calculated load current I of the motor d .

[0072] Collect the real-time current i of the motor and compare it with the calculated load current I d Do a comparison, if the difference between the two exceeds the threshold △I d , it is determined that there is foreign object intrusion, that is, there is a situation of clamping objects or people, the controller sends an alarm signal, and stops the push rod from running or controls the push rod to run in the opposite direction for a distance.

[0073] Based on the technical solution of the present invention described above, the anti-pinch method of an electric sofa is now used as an implementation case for explanation. The following parameters are only for the purpose of sorting out and understanding this case and are only for formula demonstration.

[0074] 1. Scene structure and sensor layout

[0075] Active modules: backrest extension module, seat cushion extension module (2 active modules in total);

[0076] Sensor arrangement:

[0077] A pressure sensor value g1 is set at the connection between the backrest module and the base;

[0078] Set the pressure sensor value g2 at the bottom of the cushion module;

[0079] A current sensor is installed at the power supply, and a position detection sensor is set inside the push rod to detect the angular displacement θ;

[0080] 2. Parameter settings:

[0081] The motor moment of inertia J is a common parameter of DC motors and is selected according to the power of the sofa push rod and is set to 0.0001 kg·m 2 ;

[0082] Torque coefficient K e The motor structure fixed parameters are set to 0.5N·m / A;

[0083] The pressure sensor's own weight △g1 is the basic pressure of the module's own weight on the pressure sensor, which is set to 30N (the weight of the backrest module);

[0084] The pressure sensor's own weight △g2 is the basic pressure of the module's own weight on the pressure sensor, which is set to 50N (the weight of the cushion module);

[0085] First-order influence coefficient k 11 is the first-order linear influence coefficient of unit pressure on load torque, which is set to 0.002 N·m / N (backrest module);

[0086] First-order influence coefficient k 21 is the first-order linear influence coefficient of unit pressure on load torque, which is set to 0.002 N·m / N (seat cushion module);

[0087] Second-order influence coefficient k 12 is the second-order linear influence coefficient of the unit pressure square on the load torque, set to 0.000003N·m / N 2 (backrest module);

[0088] Second-order influence coefficient k 22is the second-order linear influence coefficient of the unit pressure square on the load torque, set to 0.000003N·m / N 2 (seat cushion module);

[0089] The friction torque increment △TL1 is the friction loss of the backrest module and is set to 0.08 N·m;

[0090] The friction torque increment △TL2 is the friction loss of the seat cushion module, which is set to 0.12 N·m;

[0091] The relationship between the push rod stroke and angular displacement is: for every 1mm of push rod movement, the motor angular displacement increases by 120 radians, 1mm = 120 radians (θ = 120 × stroke radians);

[0092] Current error threshold △Id: When the difference between the measured current and the calculated current exceeds 0.4A, anti-pinch is triggered, set to 0.4A;

[0093] 3. The anti-pinch control process is as follows:

[0094] Scenario establishment: A child accidentally crawls under the sofa seat while it is retracting:

[0095] Data collection:

[0096] Pressure sensor g1+△g1=230N (pressure applied by the backrest + pressure caused by the module's own weight).

[0097] Pressure sensor g2+△g2=300N (pressure applied by the seat + pressure caused by the module's own weight).

[0098] The motor angular displacement θ = 18000 radians (the push rod stroke is 150 mm).

[0099] The measured current i=4.5A.

[0100] Load torque calculation:

[0101] According to T Lx =k x1 *(g x +△g x )+k x2 *(g x +△g x ) 2 +△T Lx

[0102] Get the seat module load torque T L2 is 1N·m, and the backrest module load torque T L1 is 0.7N·m; the total load torque is 1.7N·m.

[0103] Motor current calculation:

[0104] Motor angular velocity When no one or object is caught, the motor moves at a constant speed. m =60rad / s. At the moment of clamping a person or object, the motor speed does not have time to change due to the influence of electromechanical inertia.

[0105] Torque increment Jdω m / dt=0 (acceleration is 0 at uniform speed);

[0106] Substitution

[0107] Anti-pinch judgment: If the calculated current I d ≈3.4A, the measured current i=4A, the difference 0.6A>threshold 0.4A, triggering the anti-pinch function, the sofa stops extending and moves back.

[0108] Based on the technical solution of the present invention described above, the anti-pinch method of an electric recliner is now used as an implementation case for explanation. The following parameters are only for the purpose of clarifying and understanding this case and are only for formula demonstration.

[0109] 1. Scene structure and sensor layout

[0110] Active modules: backrest extension module, seat cushion extension module, calf extension module (3 active modules in total);

[0111] Sensor arrangement:

[0112] A pressure sensor value g1 is set at the connection between the backrest module and the base;

[0113] Set the pressure sensor value g2 at the bottom of the cushion module;

[0114] Set the pressure sensor value g3 at the bottom of the calf module;

[0115] A current sensor is installed at the power supply, and a position detection sensor is set inside the push rod to detect the angular displacement θ;

[0116] 2. Parameter settings:

[0117] The motor moment of inertia J is a common parameter of DC motors and is selected according to the power of the sofa push rod and is set to 0.0001 kg·m 2 ;

[0118] Torque coefficient K e The motor structure fixed parameters are set to 0.5N·m / A;

[0119] The pressure sensor's own weight △g1 is the basic pressure of the module's own weight on the pressure sensor, which is set to 30N (the weight of the backrest module);

[0120] The pressure sensor's own weight △g2 is the basic pressure of the module's own weight on the pressure sensor, which is set to 50N (the weight of the cushion module);

[0121] The pressure sensor's own weight △g3 is the basic pressure of the module's own weight on the pressure sensor, which is set to 30N (the weight of the calf module);

[0122] First-order influence coefficient k 11 is the first-order linear influence coefficient of unit pressure on load torque, which is set to 0.002 N·m / N (backrest module);

[0123] First-order influence coefficient k 21 is the first-order linear influence coefficient of unit pressure on load torque, which is set to 0.002 N·m / N (seat cushion module);

[0124] First-order influence coefficient k 31 is the first-order linear influence coefficient of unit pressure on load torque, which is set to 0.002 N·m / N (calf module);

[0125] Second-order influence coefficient k 12 is the second-order linear influence coefficient of the unit pressure square on the load torque, set to 0.000003N·m / N 2 (backrest module);

[0126] Second-order influence coefficient k 22 is the second-order linear influence coefficient of the unit pressure square on the load torque, set to 0.000003N·m / N 2 (seat cushion module);

[0127] The second-order influence coefficient k32 is the second-order linear influence coefficient of the unit pressure square on the load torque, which is set to 0.000003N·m / N 2 (calf module);

[0128] The friction torque increment △TL1 is the friction loss of the backrest module and is set to 0.08 N·m;

[0129] The friction torque increment △TL2 is the friction loss of the seat cushion module, which is set to 0.12 N·m;

[0130] The friction torque increment △TL3 is the friction loss of the calf module, which is set to 0.05 N·m;

[0131] The relationship between the push rod stroke and angular displacement is: for every 1mm of push rod movement, the motor angular displacement increases by 120 radians, 1mm = 120 radians (θ = 120 × stroke radians);

[0132] Current error threshold △Id: When the difference between the measured current and the calculated current exceeds 0.4A, anti-pinch is triggered, set to 0.4A;

[0133] 3. The anti-pinch control process is as follows:

[0134] Scenario setup: A child accidentally crawls under the electric recliner's calf area during its retraction process:

[0135] Data collection:

[0136] Pressure sensor g1+△g1=230N (pressure applied by the backrest + pressure caused by the module's own weight), that is, the backrest is not under pressure.

[0137] Pressure sensor g2+△g2=250N (pressure applied by the seat + pressure caused by the module's own weight),

[0138] Pressure sensor g2+△g2=150N (pressure applied by the calf + pressure caused by the module's own weight).

[0139] The motor angular displacement θ = 18000 radians (the push rod stroke is 150 mm).

[0140] The measured current i=4.5A.

[0141] Load torque calculation:

[0142] According to T Lx =k x1 *(g x +△g x )+k x2 *(g x +△g x ) 2 +△T Lx

[0143] Get the calf module load torque T L3 The load torque of the seat module is 0.42N·m. L2 The load torque of the backrest module (assuming no additional pressure) is 0.8N·m. L1 is 0.7N·m; the total load torque is 1.92N·m.

[0144] Motor current calculation:

[0145] Motor angular velocity When no one or object is caught, the motor moves at a constant speed. m =60rad / s. At the moment of clamping a person or object, the motor speed does not have time to change due to the influence of electromechanical inertia.

[0146] Torque increment Jdω m / dt=0 (acceleration is 0 at uniform speed);

[0147] Substitution

[0148] Anti-pinch judgment: If the calculated current I d ≈3.85A, the measured current i=4.5A, the difference 0.7A>threshold 0.4A, triggering the anti-pinch function, the sofa stops extending and moves back.

[0149] The present invention arranges the current detection sensor inside the push rod, power supply, and hand controller. There is no movement inside the above components, which does not affect the cable life; the motor mechanical angular displacement detection sensor added by the present invention is inside the push rod and is a fixed part, which does not affect the cable life; the pressure sensor added by the present invention is in a supporting position such as a seat or leg, the sensor cable is easy to install, and the movement has little effect on the sensor cable, and the cable life is very little affected.

[0150] The present invention uses a load observer to calculate the load current in real time and compare it with the measured current fed back by the current sensor. As long as there is a person or object trapped, regardless of the location, the motor's load torque will change. Therefore, regardless of the location of the person or object trapped, the method of the present invention can detect and control it.

[0151] The present invention detects the pressure sensor data while detecting the current, which can ensure the consistency of the data for passengers of different weights and body shapes; the present invention also detects the mechanical angular displacement of the motor, which can ensure the consistency of the data under different strokes of the push rod. Therefore, the present invention can effectively detect whether there is a person or object being pinched.

[0152] Although the present invention has been described in detail above using general descriptions and specific embodiments, it will be apparent to those skilled in the art that modifications and improvements may be made thereto. Therefore, such modifications and improvements, without departing from the spirit of the present invention, are intended to be within the scope of protection claimed herein.

Claims

1. A method for controlling anti-pinch in intelligent furniture, characterized by: The push rod drives the overall frame of the smart furniture composed of various movable modules to complete the stretching and folding of the smart furniture, including the following steps: Step 1: Set up pressure sensors at each active module of the smart furniture to obtain the pressure value g of each active module of the smart furniture x By setting a current sensor at the power supply or hand controller of the smart furniture, the current current of the motor can be obtained; by setting a position detection sensor inside the push rod, the mechanical angular displacement θ of the motor or the push rod stroke can be obtained; Step 2: The load torque applied by each active module of the smart furniture to the push rod; Step 3: Based on step 2, the total load torque of the push rod during the extension and retraction of the smart furniture is obtained; Step 4: Calculate the normal motor current value based on the obtained total load torque and motor mechanical angular displacement. Compare the current motor current value with the calculated normal motor current value. Based on the error, determine whether a person or object is trapped. If a person or object is trapped, enable the anti-pinch function.

2. The anti-pinch control method for intelligent furniture according to claim 1, characterized in that: The movable modules of the overall frame of the intelligent furniture are hingedly connected by connecting rods or slide rails.

3. The anti-pinch control method for intelligent furniture according to claim 1, characterized in that: The electromagnetic torque output by the push rod at any time should be equal to the total load torque of the frame and the torque increment caused by the speed change, that is, it satisfies the basic motion equation: Where J is the mechanical moment of inertia of the motor; ω m is the mechanical angular velocity of the motor, which is calculated by the mechanical angular displacement θ of the motor or the change in the push rod stroke; T e is the electromagnetic torque, T L is the load torque; When the push rod is a DC motor, the electromagnetic torque of the push rod is related to the torque coefficient and motor current of the motor, that is: T e =K e I d (2); Among them, K e is the torque coefficient of the motor, which is related to the motor structure. Once the motor is determined, the coefficient remains unchanged; I d is the load current; Combining equations (1) and (2), we get the load current I d :

4. The anti-pinch control method for intelligent furniture according to claim 1, characterized in that: Assume that the detection data of the pressure sensor group composed of the pressure sensors of each active module are g x (x=1,2..,n), then the load torque T applied by each active module of the current intelligent furniture to the push rod is obtained Lx , T Lx Expressed as: T Lx =k x1 *(g x +△g x )+k x2 *(g x +△g x ) 2 +△T Lx (4) Among them, g x Indicates the pressure sensor data corresponding to each active module, △g x Indicates the pressure caused by the weight of each active module, k x1 k represents the first-order influence coefficient of the unit pressure of each active module on the push rod load torque, x2 Indicates the second-order influence coefficient of the unit pressure of each active module on the push rod load torque, △T Lx Indicates the load torque increment caused by friction of each active module.

5. The anti-pinch control method for intelligent furniture according to claim 1, characterized in that: The first-order and second-order influence coefficients k of unit pressure on the load torque of the push rod x1 、k x2 The change of each operating state during the stretching process of the smart furniture leads to k x1 、k x2 With the stroke of the push rod, k x1 、k x2 is a piecewise constant related to the push rod stroke. The push rod stroke is linearly related to the mechanical angular displacement θ of the motor, so k x1 、k x2 The mechanical angular displacement θ of the motor changes in stages, that is: k x1 =f 1x (i) k x2 =f 2x (i) (5) Therefore, the load torque T of each active module of the smart furniture on the push rod Lx As the push rod stroke and the motor's mechanical angular displacement θ change, during the operation of smart furniture, the load torque T of each active module on the push rod Lx The mechanical angular displacement θ of the motor or the stroke of the push rod, and the pressure sensor data g x Related: T Lx =f(g x ,i) (6) During the operation of smart furniture, the total load torque of the push rod is expressed as the sum of the load torques of each active module, that is: Therefore, the total load torque is related to the motor's mechanical angular displacement θ or the push rod stroke and the pressure sensor data g x Related; During the operation of the push rod, the pressure sensor data of each active module is detected g x Substitute the motor mechanical angular displacement θ or the push rod stroke into equations (4) and (7) to obtain the push rod load torque; The push rod load torque T L Enter the above formula (3) to get the calculated load current I of the motor d .

6. The anti-pinch control method for intelligent furniture according to claim 5, characterized in that: Collect the real-time current i of the motor and compare it with the calculated load current I d Do a comparison, if the difference between the two exceeds the threshold △I d , it is determined that there is foreign object intrusion, that is, there is a situation of clamping objects or people, the controller sends an alarm signal, and stops the push rod from running or controls the push rod to run in the opposite direction for a distance.

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