Intelligent cat litter box with anti-pinch multi-protection strategy

Abstract

The utility model discloses a kind of intelligent cat litter box with anti-pinch cat multiple protection strategy belongs to pet intelligence article technical field.The cat litter box includes drum structure, drum driving motor, main control unit MCU, infrared detection unit, weight detection unit and current detection unit.Infrared detection unit is used to detect pet in and out, weight detection unit is used to judge whether pet is in basin, current detection unit is used to real-time monitoring motor load current.When infrared or weight detection unit detects pet existence, main control unit suspends drum motor operation;When motor current rises slope exceeds preset threshold, main control unit judges as cat event and immediately reversely rotates drum to loosen foreign matter.The utility model is combined by multiple sensing detection and current characteristic identification, realizes quick protection and abnormal identification, significantly improves the safety and reliability of intelligent cat litter box.

Description

Technical Field

[0001] This utility model relates to the field of cat litter boxes, specifically to an intelligent cat litter box with multiple protection strategies to prevent cats from being pinched. Background Technology

[0002] With the rapid development of the pet economy, the number of cat-owning households is increasing year by year, and the pet supplies market is gradually becoming more intelligent and automated. Among them, smart litter boxes, as representative products that can automatically clean cat litter and reduce manual labor, have become mainstream in smart pet devices. However, existing smart litter boxes generally have safety hazards during the automatic cleaning process, especially in the roller-type cleaning structure. When the cat has not completely left or re-entered the litter box, the roller drive mechanism starts, which can easily cause the pet's tail or body parts to be pinched, endangering the pet's safety and affecting the user experience.

[0003] Currently, some smart litter boxes on the market attempt to implement safety detection by adding sensors. For example, a common solution is to install an infrared beam sensor at the litter box entrance; when the beam is blocked, the system determines that a pet has entered, thus pausing the cleaning process. Other products use weight sensors at the bottom of the litter box; when a change in load is detected, it infers whether a pet is inside. However, these solutions still suffer from insufficient reliability.

[0004] First, infrared sensors are easily affected by external factors such as dust obstruction and light interference, resulting in false alarms or missed alarms, making it impossible for the system to accurately determine whether a pet is in a dangerous area. Second, weight sensors can only reflect the overall load status. When a cat stays in a specific posture in the edge area, the weight signal changes very little and cannot be detected. In addition, the redundancy of a single detection mechanism is low. Once the sensor malfunctions or misjudges, the system will lose its safety protection function, thus posing a risk of the cat being trapped.

[0005] Therefore, to improve the safety and system reliability of smart litter boxes during automatic cleaning, it is urgent to propose a protective structure for smart litter boxes with multiple anti-pinch detection mechanisms. This structure should not only be able to detect the presence of pets through infrared and weight sensors, but also perform secondary judgment by combining the current characteristic signal of the motor's operating status itself. It should monitor changes in motor load from an electrical perspective to promptly identify and execute a reverse loosening operation when a pet or foreign object enters the danger zone, thereby achieving true "dual protection of hardware and software".

[0006] In conclusion, existing smart litter boxes still have significant shortcomings in safety protection design and cannot provide comprehensive protection for pets in complex scenarios. Summary of the Invention

[0007] To address the aforementioned issues, this invention provides an intelligent cat litter box with multiple anti-pinch protection strategies, effectively resolving these problems and significantly improving the safety and stability of the device during use.

[0008] This utility model is achieved through the following technical solution: a smart cat litter box with multiple anti-pinch protection strategies, comprising: The roller structure is used to hold cat litter and achieves automatic cleaning through rotation; A roller drive motor is used to drive the roller structure to rotate; The main control unit (MCU) is electrically connected to the roller drive motor and is used to control the start, stop and direction of the motor. An infrared detection unit is installed at the entrance of the litter box to detect when a pet enters or exits. The weight detection unit, located at the bottom of the litter box or on the foot pedal, is used to detect whether the pet is inside the box. A current detection unit is connected to the power supply circuit of the drum drive motor and is used to detect changes in the motor load current in real time. The main control unit (MCU) is electrically connected to the infrared detection unit, the weight detection unit, and the current detection unit, respectively. When the infrared detection unit or weight detection unit detects the presence of a pet, the main control unit (MCU) controls the roller drive motor to stop running. When the current detection unit detects that the rising slope K of the current change of the roller drive motor exceeds the preset threshold, the main control unit MCU determines it as a cat-clamping event and immediately controls the roller drive motor to stop running and rotate in the opposite direction by a preset angle.

[0009] As a preferred technical solution, the current detection unit includes a current sampling resistor and an amplification circuit. The output terminal of the amplification circuit is electrically connected to the ADC input terminal of the main control unit, and is used to convert the current change into a detectable voltage signal.

[0010] As a preferred technical solution, the amplifier circuit is constructed using an LM321 amplifier chip, with the input terminal connected across the current sampling resistor and the output terminal connected to the analog-to-digital conversion interface of the main control unit via a filter capacitor.

[0011] As a preferred technical solution, the main control unit (MCU) stores a current change determination algorithm, which calculates the slope of the current change. It is then compared with a set threshold to determine whether it is a cat-clamping incident.

[0012] As a preferred technical solution, when the main control unit controls the motor to rotate in the reverse direction, it adjusts the angle and speed of the reverse rotation by controlling the PWM signal.

[0013] As a preferred technical solution, the infrared detection unit is positioned above the litter box entrance and uses beam blocking to identify pets entering and exiting.

[0014] As a preferred technical solution, the weight detection unit is a strain gauge pressure sensor, which is installed below the bottom support plate of the litter box to detect load changes and determine whether the pet has left.

[0015] As a preferred technical solution, the main control unit is also connected to a buzzer or voice module to issue an alarm when a cat-clamping event is detected.

[0016] As a preferred technical solution, a relay or MOSFET drive circuit is provided between the roller drive motor and the main control unit to realize motor start-stop and reverse control.

[0017] As a preferred technical solution, the main control unit is connected to a wireless communication module to remotely monitor the status of the litter box and record log information of cat-clamping events.

[0018] The beneficial effects of this invention are: This invention significantly improves the reliability of safety protection through a redundant design with multiple detection mechanisms. The device integrates an infrared detection unit, a weight detection unit, and a current detection unit, which work together to detect the pet's status at different stages. When the infrared sensor detects that the pet has not left the litter box or the weight sensor detects that there is still a load, the main control unit (MCU) can immediately pause the roller cleaning action, thereby preventing cat-clamping incidents at the primary level.

[0019] Secondly, this invention innovatively introduces a motor current change feature recognition algorithm, which monitors the working status of the roller drive motor in real time through a current detection unit. The main control unit (MCU) determines the operating status based on the detected current rise slope. The system determines whether the load is abnormal, and automatically identifies events such as a cat being caught or a foreign object being stuck when the slope exceeds a preset threshold. Compared to traditional methods that rely solely on sensor signals, this solution enables dynamic safety protection based on the motor's own load feedback. It can still respond accurately even if the infrared and weight sensors fail or misjudge, thereby effectively improving the overall safety level.

[0020] Furthermore, this invention incorporates an intelligent reverse loosening control strategy. Upon detecting a cat-clamping incident, the main control unit immediately stops the motor and rotates it in the opposite direction at a preset angle with adjustable speed, disengaging the roller from the object and preventing secondary pinching injuries caused by mechanical inertia or control lag. This strategy, combined with the motor's PWM speed control output, achieves smooth and precise reverse action, further enhancing the system's flexible response capability.

[0021] Furthermore, the current detection circuit of this invention employs a combination of an LM321 amplifier chip and a precision sampling resistor, offering advantages such as high response speed and low error rate. It can complete current signal amplification and transmission within milliseconds, ensuring the judgment accuracy of the main control unit. The infrared detection and weight detection units utilize a modular installation method, facilitating user maintenance and replacement, and enhancing product lifespan and scalability. In addition, this utility model can be optionally equipped with a buzzer or voice alarm module, which can immediately issue an audible and visual alert when a cat-clamping incident is detected, reminding the user to intervene in time; through the wireless communication module, remote monitoring of the device status and fault recording can be realized, providing data support for subsequent product maintenance and further improving the user experience. Attached Figure Description

[0022] 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.

[0023] Figure 1 This is the motor drive circuit diagram of this utility model; Figure 2 This is the circuit diagram for the current detection of this utility model. Detailed Implementation

[0024] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0025] Any feature disclosed in this specification (including any appended claims, abstract, and drawings) may be replaced by other equivalent or similar features for a similar purpose, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0026] like Figure 1 and Figure 2 As shown, this utility model discloses an intelligent cat litter box with multiple protection strategies against cat pinching. In its specific implementation, it includes a roller structure, a roller drive motor, a main control unit (MCU), an infrared detection unit, a weight detection unit, a current detection unit, an alarm prompt unit, a drive control circuit, and a wireless communication module. The various units are electrically connected through signal lines or circuit boards to form an overall control system, which is used to realize safety protection and intelligent management functions during the automatic cleaning process of cat litter.

[0027] In its actual structure, the roller is installed in the middle of the litter box shell, and its interior is used to hold cat litter. The outer wall of the roller is fixedly connected to the output end of the roller drive motor via a drive shaft. The roller is made of high-strength, corrosion-resistant material, and its inner wall is equipped with agitator blades to rotate the cat litter during rolling, separating solid excrement from the dry litter. The rotation of the roller is controlled by the roller drive motor. When the motor is powered on, it drives the roller to rotate in a set direction, thereby achieving automatic cleaning. The motor is preferably a low-noise DC geared motor, which can provide stable torque at low speeds, ensuring smooth cleaning.

[0028] The main control unit (MCU) is the core control module of the entire litter box. It is installed in the electrical control box and is electrically connected to the roller drive motor, infrared detection unit, weight detection unit, current detection unit, buzzer or voice module, and wireless communication module. The main control unit can use an STM32 series microcontroller or an equivalent low-power microcontroller chip, internally integrating an analog-to-digital converter (ADC) interface, PWM control port, and multi-channel input / output interfaces. The main control unit has a built-in anti-pinch logic algorithm that can determine in real time whether there is a pet in the litter box and whether an abnormal pinching event has occurred based on the combined changes in infrared, weight, and current signals, and execute corresponding protective actions.

[0029] The infrared detection unit is installed above the litter box entrance, with the transmitter and receiver positioned opposite each other to form a stable infrared beam channel. When a pet enters or leaves the litter box, its body blocks the infrared beam. The main control unit determines the pet's entry or exit status based on the beam interruption signal. Before cleaning inside the litter box, the main control unit first checks the infrared channel status. If it detects beam interruption, it assumes the cat is still in or near the litter box and pauses the start command of the roller motor. The infrared detection module uses an anti-interference infrared sensor, effectively resisting false triggering caused by external light and dust, thus ensuring the stability of signal detection.

[0030] The weight detection unit is mounted on the support structure at the bottom of the litter box, preferably using a strain gauge pressure sensor. A force transmission structure is formed between the sensor and the litter box base via a metal elastomer. When a cat enters the litter box, the base undergoes a slight deformation, and the pressure sensor outputs a corresponding voltage signal. The main control unit samples this signal change in real time via an analog-to-digital converter to determine if the cat is still inside the litter box. When the detected load signal exceeds a preset threshold, the main control unit holds the cleaning program in a standby state until the load signal returns to the baseline level before allowing the roller drive motor to start the cleaning process. This detection unit effectively prevents pets from being pinched during cleaning, making it particularly suitable for lightweight kittens.

[0031] To further improve the reliability of the anti-pinch protection, this invention incorporates a current detection unit for real-time monitoring of load current changes in the roller drive motor. This current detection unit comprises a current sampling resistor R137, an operational amplifier chip U10 (LM321), filter capacitors, and a resistor network R142 and R143. The current sampling resistor is connected in series in the power supply circuit of the roller drive motor. When the motor is running, changes in its load cause current changes, resulting in a corresponding voltage drop across the current sampling resistor. The input terminal of the LM321 amplifier chip is connected across this resistor, amplifying the small voltage signal before outputting it to the ADC interface of the main control unit. The output terminal is also connected in parallel with filter capacitors C69 and C70 and a current-limiting resistor R144 to filter out high-frequency noise and ensure a smooth and stable signal.

[0032] When the litter box is running normally, the operating current of the roller motor is stable at the set value A. When a foreign object gets stuck or a pet enters the inside of the roller, the rotational resistance of the roller suddenly increases, causing the current to rise rapidly to point B in a very short time. After sampling the current signal, the main control unit calculates the current rise slope through an internal algorithm. When the K value exceeds the set threshold When the system detects an incident involving a cat being caught or a foreign object, the main control unit immediately issues an emergency stop command. This cuts off the motor's power supply via the drive circuit and, after a very short delay, sends a reverse control signal, causing the roller motor to rotate in the opposite direction at a preset PWM duty cycle, thus releasing the gripping part and ensuring the pet's safety. The entire detection and response process can be completed within milliseconds, significantly reducing the risk of mechanical injury.

[0033] When the motor rotates in reverse, the main control unit dynamically adjusts the frequency and duty cycle of the PWM output signal to control the reverse angle and speed, preventing excessive reverse rotation that could cause litter to spill or result in secondary clamping. The reverse rotation angle can be set via software, for example, to 10%–20% of the forward rotation angle, and the system automatically returns to a stationary state after execution. The anti-pinch algorithm stored in the main control unit can adjust threshold parameters according to different litter box models, roller diameters, and motor characteristics to achieve a balance between versatility and accuracy.

[0034] In terms of electrical connection, the drum drive motor and the main control unit are connected via a relay or MOSFET drive circuit. The drive circuit can use a bidirectional MOSFET structure to control the forward and reverse rotation of the motor. The main control unit outputs a signal through the PWM port, which is amplified by the drive transistor to control the motor's on / off state and direction switching. The relay drive scheme is suitable for high-power motors. The control signal output by the main control unit drives the relay coil to switch on and off, thereby controlling the polarity reversal of the voltage across the motor to achieve fast and reliable motor start-stop.

[0035] To enhance user experience, this invention also includes an alarm notification unit. When the main control unit detects a cat being trapped or an abnormal current, it will simultaneously trigger a buzzer or voice module to emit a warning sound or voice prompt, reminding the user to check the device status promptly. The alarm unit is connected to the digital output interface of the main control unit, and the alarm time and volume can be controlled via a program. This alarm device not only provides immediate alerts when a pet is trapped, but also provides notifications when the system experiences motor overload, sensor malfunctions, or other issues, enhancing the device's human-machine interaction capabilities.

[0036] In addition, the main control unit can be connected to a wireless communication module to enable smart networking. The wireless module can be a Wi-Fi or Bluetooth Low Energy (BLE) module, capable of communicating with a mobile app or a home smart hub. Users can view the litter box's operating status, pet usage records, and anti-pinch event logs in real time via their mobile devices. When the system detects a cat-pinch event, the wireless module can upload the event time, current change curve, and response action record to the cloud for subsequent maintenance and algorithm parameter optimization.

[0037] This invention achieves dual determination of pet presence and clamping risk through multi-dimensional joint detection by infrared detection unit, weight detection unit, and current detection unit. Real-time analysis of motor load characteristic signals and intelligent reverse control strategy effectively avoid protection failure caused by a single sensor malfunction, significantly improving the safety and stability of the equipment. Based on circuit principles, the current detection channel using the LM321 amplifier circuit features fast response and high sensitivity, accurately matching the MCU's ADC sampling terminal to ensure protective actions are executed in a very short time. This invention achieves closed-loop control across the entire chain from detection and identification to protective action, with tight hardware and software integration, full disclosure, and a reasonable structure, possessing high practical value and promising prospects for widespread application.

[0038] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any changes or substitutions conceived without inventive effort should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope defined in the claims.

Claims

1. A smart cat litter box with multiple anti-pinch protection strategies, characterized in that, include: The roller structure is used to hold cat litter and achieves automatic cleaning through rotation; A roller drive motor is used to drive the roller structure to rotate; The main control unit (MCU) is electrically connected to the roller drive motor and is used to control the start, stop and direction of the motor. An infrared detection unit is installed at the entrance of the litter box to detect when a pet enters or exits. The weight detection unit, located at the bottom of the litter box or on the foot pedal, is used to detect whether the pet is inside the box. A current detection unit is connected to the power supply circuit of the drum drive motor and is used to detect changes in the motor load current in real time. The main control unit (MCU) is electrically connected to the infrared detection unit, the weight detection unit, and the current detection unit, respectively. When the infrared detection unit or weight detection unit detects the presence of a pet, the main control unit (MCU) controls the roller drive motor to stop running. When the current detection unit detects that the rising slope K of the current change of the roller drive motor exceeds the preset threshold, the main control unit MCU determines it as a cat-clamping event and immediately controls the roller drive motor to stop running and rotate in the opposite direction by a preset angle.

2. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 1, characterized in that: The current detection unit includes a current sampling resistor and an amplifier circuit. The output of the amplifier circuit is electrically connected to the ADC input of the main control unit and is used to convert the current change into a detectable voltage signal.

3. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 2, characterized in that: The amplifier circuit is constructed using an LM321 amplifier chip. The input terminal is connected across the current sampling resistor, and the output terminal is connected to the analog-to-digital conversion interface of the main control unit via a filter capacitor.

4. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 1, characterized in that: The main control unit (MCU) stores a current change determination algorithm, which calculates the slope of the current change. It is then compared with a set threshold to determine whether it is a cat-clamping incident.

5. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 1, characterized in that: When the main control unit controls the motor to rotate in reverse, it adjusts the angle and speed of the reverse rotation by controlling the PWM signal.

6. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 1, characterized in that: The infrared detection unit is positioned above the litter box entrance and uses beam blocking to identify pets entering and exiting.

7. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 1, characterized in that: The weight detection unit is a strain gauge pressure sensor, installed below the support plate at the bottom of the litter box, used to detect load changes and determine whether the pet has left.

8. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 1, characterized in that: The main control unit is also connected to a buzzer or voice module, which will issue an alarm when a cat-clamping event is detected.

9. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 1, characterized in that: A relay or MOSFET drive circuit is provided between the drum drive motor and the main control unit to realize the motor start-stop and reverse control.

10. The intelligent cat litter box with multiple anti-pinch protection strategies according to claim 1, characterized in that: The main control unit is connected to the wireless communication module to remotely monitor the status of the litter box and record log information of cat-clamping incidents.

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