Patent Description:
Electric lift platforms are generally applied in houses, offices and medical facilities, such as height-adjustable writing desks, kitchen islands, tatamis, office desks, and hospital beds, etc. If the platform or its frame hits an obstacle during lift adjustment, a surrounding structure or the structure of the platform proper could be possibly damaged; it also poses a risk of impacting or squeezing the human body. With the ever-higher demand on product safety, impact detection and obstruction-hitting handling of a lift platform become more and more important.

The existing impact detection schemes for lift platforms on the market mainly include: <NUM>. current characteristic detection upon impact; <NUM>. mechanical sensor-based detection, wherein the mechanical sensor includes a piezoelectric material, a piezoresistive material, and a spring; <NUM>. desktop tilt angle detection. However, experimental analysis and empirical examination reveal that the scheme of current characteristic detection upon impact has a poor sensitivity, is largely susceptible to temperature, and is easily affected by assembly of the lift platform; besides, when the platform is loaded, the current variation is small, such that a reliable impact detection can hardly be achieved, which degrades the safety. As to the scheme of mechanical sensor-based detection, the sensor is required to directly or indirectly contact with a stress-bearing surface, such that to guarantee the sensibility, the sensor has to be installed at a position with a prominent stress variation, posing a higher requirement on installation. As to the scheme of desktop tilt angle detection, a very large pressure is required for a soft impact to cause variation of the tilt angle, which greatly degrades the safety.

<CIT> and <CIT> relate to an electric lift platform according to the preamble of claim <NUM>.

An objective of the present disclosure is to provide an electric lift platform retractable upon hitting an obstruction, which is more sensitive and safer.

The above objective is achieved by the electric lift platform according to claim <NUM>. Advantageous developments thereof are defined in the dependent claims.

With the above technical solutions, the present disclosure offers the following advantages:.

Hereinafter, the present disclosure will be further illustrated with reference to the accompanying drawings:.

Lifting column; <NUM>. Desktop; <NUM>. Transverse beam; <NUM>. Controller; <NUM>. Power supply module; <NUM>. MCU; <NUM>. Motor driver circuit; <NUM>. Feedback circuit; <NUM>. Data communication port; <NUM>. Manipulator; <NUM>. Multi-axis sensor module; <NUM>. MPU <NUM> module; <NUM>. Three-axis accelerometer; <NUM>. Three-axis gyroscope; <NUM>. Central processing unit; <NUM>. Filtering module; <NUM>. Three-axis magnetometer.

As shown in <FIG>, the present disclosure discloses an electric lift platform retractable upon hitting an obstruction. In this embodiment, the electric lift platform is an electric liftin desk, such that the platform refers to the desktop of the electric lift desk. The electric lift desk comprises a lifting column <NUM>, a desktop <NUM>, a controller <NUM>, a manipulator <NUM>, and a multi-axis sensor module <NUM> for acquiring platform obstruction-hitting data, wherein the multi-axis sensor module <NUM> acquires variations of motion statuses of the desktop <NUM> along different axes, satisfying detection of motion statuses of the desktop <NUM> caused by different obstacles at different positions; besides, the detection is not affected by assembly of the lift platform and is less demanding on the installation position. Further, the sensor is not required to directly contact with the stress-bearing surface, and even an impact with a smaller stress can be detected, thereby offering a higher detection sensitivity. The controller <NUM> comprises a power supply module <NUM>, a main control unit MCU <NUM>, and a motor driver circuit <NUM>, wherein the output end of the MCU <NUM> is connected to the motor driver circuit <NUM>, and the multi-axis sensor module <NUM> is connected to the input end of the MCU <NUM>, such that the MCU <NUM>, after having processed the obstruction-hitting data, transmits a control signal to the motor driver circuit <NUM>, and the latter controls the lifting column <NUM> to execute a corresponding retract action; in this way, safety of the electric lift platform is significantly improved. In this example, the MCU adopts a Freescale HCS08 family microcontroller, which is reliable in motor driver applications; in this way, reliability of the electric lift platform is improved.

In this embodiment, the obstruction-hitting data include accelerations along the X-axis, Y-axis, and Z-axis and/or angular velocities along the three axes; the plane where the desktop <NUM> is located is a plane formed between any two of the X-axis, Y-axis, and Z-axis; and the obstruction-hitting data as acquired include the accelerations along the three axes and/or the angular velocities along the three axes;. The three-axis data acquisition offers a higher detection sensitivity. Besides, with the three-axis data, detection can be still implemented even the desktop <NUM> does not tilt. With the accelerations along the three axes as an example, wherein the plane formed between X-axis and Y-axis is the plane where the desktop <NUM> is located, when the desktop <NUM> is vertically stressed and the desktop <NUM> only vibrates vertically in the Z-axis direction, the accelerations along the X-axis and Y-axis approach to zero, but the acceleration variation of Z-axis is significant. In this case, the controller <NUM> actuates the lifting column to execute a retract action. With this control manner, the multi-axis sensor module can directly implement sensing without sensing the tilt angle of the platform. Therefore, the actuation manner in this embodiment is not restricted by whether the desktop <NUM> tilts, and even the desktop <NUM> does not tilt, it can be still sensed that the desktop <NUM> hits an obstacle. In this way, more platform accidental situations can be sensed with a higher sense speed, a higher sensitivity, and a higher accuracy; further, due to not relying on a tilt angle of the desktop <NUM>, the judgement can be performed before tilting of the desktop.

In this embodiment, the multi-axis sensor module <NUM> is preferably installed in the controller <NUM>, such that installation of the multi-axis sensor module is not restricted by the fitting degree with other components of the electric lift platform or restricted to a specific stress-bearing mechanism, thereby simplifying the assembly process between the lifting column and an electric push rod, increasing stability of the entire electric lift platform, and improving quality of assembly. Besides; the multi-axis sensor module does not affect installation and assembly of the transmission part of the lift platform per se, does not destroy the simplicity and aesthetics of the appearance of the lift platform, has no extra installation requirement for the user, and simplifies installation steps.

The multi-axis sensor module <NUM> includes a six-axis sensor module and a central processing unit. The six-axis sensor module has a plurality of models and specifications, e.g., an MPU6050 module, or an LCM20608D module, or an LSM6DSL module. In this example, the six-axis sensor is an MPU6050 module. The MPU6050 module <NUM> includes a three-axis accelerometer <NUM> for acquiring three-axis acceleration data and a three-axis gyroscope <NUM> for acquiring three-axis angular velocities. By detecting variations of multi-dimensional accelerations and multi-axis angular velocity data at the instant of colliding between the desktop <NUM> and an obstacle, the three-axis accelerometer <NUM> and the three-axis gyroscope <NUM> realize impact detection; in this way, the detection sensibility is improved and safety of the electric lift platform is enhanced.

It needs to be noted that the three-axis gyroscope <NUM> in the MPU6050 module has a very high detection sensitivity, such that when the desktop <NUM> hits an obstacle, even the desktop <NUM> does not tilt, the three-axis gyroscope <NUM> can still detect the motion trend of the desktop <NUM>, causing variation of the three-axis angular velocity data. Likewise, the three-axis accelerometer <NUM> in the MPU6050 is also very sensitive in detection. Therefore, with such a multi-axis sensor module, the judgment does not rely on a tilt angle of the desktop <NUM>, which may be made before the desktop <NUM> tilts.

In an alternative embodiment, obstruction-hitting data may be acquired independently by the three-axis accelerometer <NUM> or the three-axis gyroscope <NUM> to judge whether the platform hits an obstacle. However, repeated experiments show that joint detection by the three-axis accelerometer <NUM> and the three-axis gyroscope <NUM> yields higher sensitivity and accuracy.

In this embodiment, the central processing unit <NUM> adopts a highly cost-effective STM32F051K86-model microcomputer. The central processing unit <NUM> is electrically connected to the MPU6050 module <NUM>. The central processing unit <NUM> or the MCU <NUM> further comprises a filter module <NUM> for filtering the three-axis acceleration data and the three-axis angular velocity data. Through data filtering, a normal lift may be distinguished from an impact, thereby avoiding misjudging a normal lift as an impact, which enhances efficiency of impact reaction. The central processing unit <NUM> is connected to the input end of the MCU42 to transmit the filtered data to the latter. The MCU <NUM>, after having processed the obstruction-hitting data, transmits a control signal to a motor driver circuit <NUM> which then controls the lifting column <NUM> to execute a corresponding retract action; in this way, the electric lift platform can efficiently and quickly react to the impact to execute a retract action, improving safety of the electric lift platform.

The multi-axis sensor module <NUM> may further comprise a three-axis magnetometer <NUM>, wherein the three-axis magnetometer <NUM> is electrically connected to the MPU6050 module <NUM>, such that the direction data acquired by the three-axis magnetometer <NUM>, together with the three-axis acceleration data and the three-axis angular data in the MUP6050 module <NUM>, are outputted to the central processing unit <NUM>. In this embodiment, the three-axis magnetometer <NUM> adopts a high-precision HMC5883L-model three-axis magnetometer. The HMC5883L-model three-axis magnetometer has been revealed in the patent number <CIT> patent, according to which, the three-axis magnetometer <NUM> may add a direction judgment to improve the detection precision of the multi-axis sensor <NUM>, causing the judgment regarding an impact more accurate and enhancing reliability of the function of the electric lift platform to retract upon hitting an obstruction; meanwhile, the three-axis magnetometer <NUM> may be extended to other applications, e.g., performing lift control to the lifting column by detecting a platform-tapping signal, so as to make the electric lift platform smarter.

In this embodiment, a preset value is set in the MCU. When the variation value of one or more of the accelerations along the X-axis, Y-axis, and Z-axis, and/or one or more of the angular velocities along the X-axis, Y-axis, and Z-axis, in the obstruction-hitting data acquired by the multi-axis sensor, exceeds the preset value by a predetermined margin within a certain time segment, the motor driver circuit controls the lifting column to execute a corresponding retract action. It needs to be noted that because this embodiment adopts a six-axis sensor, there are correspondingly six preset values, i.e., the acceleration of X-axis, the acceleration of Y-axis, and the acceleration of Z-axis, the angular velocity of X-axis, the angular velocity of Y-axis, and the angular velocity of Z-axis, all have their respective preset values. when the variation value of one or more of the six obstruction-hitting data exceeds the corresponding preset value by a preset margin, the motor driver circuit works.

It needs to be noted that the preset values and preset margins may be customized by the user dependent on different actual use environments. Additionally, in other embodiments, the preset values may also be written into the multi-axis sensor.

Additionally, it needs to be noted that to determine more accurately whether the desktop hits an obstruction, the comparative analysis may not be restricted to one comparative analysis, but may be performed between multiple time segments, wherein the variation values are compared with corresponding preset values during each time segment. For example, at the instant when the desktop hits an obstacle, its first time segment T1 is relatively short, wherein the variation values of the obstruction-hitting data in T1 are compared with corresponding preset values; after the impact time T1, a second time segment T2 is taken to compare the variation values of the obstruction-hitting data in T2 with the corresponding preset values; so on and so forth. With such multiple times of comparative analysis, the structure can be determined more accurately and misjudgment may be avoided.

The controller <NUM> further comprises a feedback circuit <NUM> for monitoring stability of the internal circuit of the controller <NUM>. The feedback circuit <NUM> constantly monitors the voltage and current statuses inside the entire controller <NUM>, and monitors information such as the motor rotating speed and operating temperature, etc., so as to adopt a corresponding protection measure to handle exceptions, e.g., Stop Error alarm, power outage, etc., which enhances safety of the controller and makes the electric lift platform more reliable.

Specifically, the filtering module <NUM> preferably adopts the Kalman filtering algorithm to perform filtering, so as to better solve the problem of Z-axis data drifting and optimize the filtering process, thereby generating a more accurate filtering result and a higher reliability of the function of the electric lift platform to retract upon hitting an obstruction.

The multi-axis sensor module <NUM> may be fixed inside the controller <NUM> via a pin header, which improves detection sensitivity and enhances safety of the electric lift platform.

The controller <NUM> is provided on the desktop <NUM>, such that it does not affect fitting with other components of the electric lift platform; instead, it improves impact detection reliability of the lift platform and greatly enhances safety of the electric lift platform.

It may be understood that the electric lift platform may also be a height adjustable kitchen island and the platform refers to the platform of the kitchen island.

It may be understood that the electric lift platform may also be a height adjustable tatami, and the platform refers to the board of the tatami.

It may be understood that the electric lift platform may also be a height adjustable hospital bed, and the platform refers to the bed board of the hospital bed.

It may be understood that the filtering module <NUM> may optionally adopt other algorithms such as margin limiting average filtering algorithm to perform filtering, as long as it can distinguish a normal lift from an impact to avoid misjudging the normal lift as an impact.

It may be understood that the multi-axis sensor module <NUM> may also be flush-jointed in the controller <NUM>.

As shown in <FIG>, the second embodiment differs from the first embodiment in that the electric lift platform further includes a transverse beam for supporting the platform.

The controller <NUM> is securely threaded to the transverse beam <NUM>. Such a setting offers an advantage that the multi-axis sensor module <NUM> may acquire obstruction-hitting data for the desktop <NUM> and the transverse beam <NUM>; besides, the installation position does not affect fitting with other components of the electric lift platform; instead, it improves impact detection reliability of the electric lift platform and significantly enhances safety of the electric lift platform. In this embodiment, the transverse beam <NUM> preferably includes two transverse bars, wherein the controller <NUM> is fixed in the space formed between the two transverse bars. It needs to be noted that the transverse beam <NUM> is not limited to the shape configuration in this embodiment, but may also be other shape configurations.

It may be understood that the controller <NUM> may also be installed on the desktop <NUM>, as long as the electric lift platform can reliably detect an impact.

As shown in <FIG>, this embodiment differs from the above embodiments in that the multi-axis sensor module is mounted in the manipulator.

A data communication port <NUM> is provided on the controller <NUM>, and the multi-axis sensor module <NUM> is provided in the manipulator <NUM>, such that the multi-axis sensor module <NUM> is electrically connected to the MCU <NUM> in the controller <NUM> via the data communication port <NUM>.

Such a setting offers an advantage that installation of the multi-axis sensor module is not restricted by the fitting degree with other components of the electric lift platform or restricted to a specific stress-bearing mechanism thereby simplifying the assembly process between the lifting column and an electric push rod, increasing stability of the entire electric lift platform, and improving quality of assembly. Besides; the multi-axis sensor module does not affect installation and assembly of the transmission part of the lift platform per se, does not destroy the simplicity and aesthetics of the appearance of the lift platform, has no extra installation requirement for the user, and simplifies installation steps.

Specifically, the multi-axis sensor module is fixed inside the manipulator via a pin header, which improves detection sensitivity and enhances safety of the electric lift platform.

It may be understood that the multi-axis sensor module is flush-jointed in the manipulator, offering a simple and convenient installation process and a high detection sensitivity.

This embodiment differs from the first embodiment in that the multi-axis sensor module here is mounted in the lifting column; because the lifting column is fixedly connected to the desktop, after an impact occurs to the desktop, the lifting column will have a corresponding motion trend. When the multi-axis sensor module is installed in the lifting column, a data communication port is provided on the controller; the multi-axis sensor module and the controller are connected via the data communication port. Of course, they may also be connected using a signal line.

Claim 1:
An electric lift platform retractable upon hitting an obstruction, comprising:
a lifting column (<NUM>), a platform (<NUM>), a transverse beam (<NUM>), a controller (<NUM>), and a manipulator (<NUM>), wherein the controller (<NUM>) comprises a main control unit, MCU (<NUM>), and a motor driver circuit (<NUM>), an output end of the MCU (<NUM>) being connected to the motor driver circuit, wherein the electric lift platform further comprises a multi-axis sensor module (<NUM>) for acquiring platform obstruction-hitting data, the multi-axis sensor module (<NUM>) being connected to an input end of the MCU (<NUM>) such that the MCU (<NUM>), after having processed the obstruction-hitting data, transmits a control signal to the motor driver circuit (<NUM>), and the latter controls the lifting column (<NUM>) to execute a corresponding retract action, the multi-axis sensor module (<NUM>) including a central processing unit (<NUM>),
characterized in that
the multi-axis sensor module (<NUM>) further includes a six-axis sensor module (<NUM>, <NUM>), the six-axis sensor module (<NUM>, <NUM>) being electrically connected with the central processing unit (<NUM>), the central processing unit (<NUM>) being connected to the input end of the MCU (<NUM>), and wherein the six-axis sensor module (<NUM>, <NUM>) includes a three-axis accelerometer (<NUM>) configured for acquiring three-axis acceleration data and a three-axis gyroscope (<NUM>) configured for acquiring three-axis angular velocity data.