Patent Description:
There is a human-boarding type electric trolley, such as an electric wheelchair, having a function of not only travelling by being operated by a person but also detecting an obstacle by an obstacle detection sensor to stop the electric trolley. In the electric trolley, in a case where an abnormality occurs in the electric trolley, the electric trolley is stopped to prevent danger due to rough driving or collision, so that safety is ensured. In the related art, in order to stop an electromotor that performs driving for travel, interruption of a power supply circuit that supplies electric power to the electromotor is performed in a case where an abnormality occurs (PTL <NUM>).

According to the present disclosure, there is provided an electric trolley that travels by controlling a motor fitted to a driving wheel of the electric trolley using a motor driver of the electric trolley, the electric trolley including a safety controller that determines whether or not to stop driving of the driving wheel, and a driving commander that outputs, to the motor driver, (i) an operation permission signal for permitting the motor to be operated and (ii) a control signal for controlling an operation of the motor, in which, when the safety controller determines to stop the driving of the driving wheel, the safety controller performs control to stop inputs of the operation permission signal and the control signal to the motor driver.

As described above, in the related art, in a case where an abnormality occurs in an electric trolley, driving of an electromotor is stopped by interrupting a power supply circuit, so that safety is ensured. However, in order to interrupt a large current supplied to the electromotor, an interruption circuit often becomes large and a weight also becomes large.

An object of the present disclosure is to provide an electric trolley capable of mounting a configuration capable of stopping travel more reliably with a small size and a light weight.

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. The same components are designated by the same reference numerals. In addition, the drawings are schematically shown with each component as a subject for easy understanding.

An electric trolley of the present disclosure will be described with reference to <FIG> and <FIG>. <FIG> is a schematic diagram of electric trolley <NUM>, which is viewed from a side surface, according to a first exemplary embodiment of the present disclosure. In addition, <FIG> is a schematic diagram of stop control according to the first exemplary embodiment of the present disclosure.

Electric trolley <NUM> includes main frame <NUM>, training wheel <NUM>, driving wheel <NUM>, motor <NUM>, brake <NUM>, power supply <NUM>, detector <NUM>, and control box <NUM>. Power supply <NUM> is a high voltage power supply, and supplies electric power to motor driver <NUM>, motor <NUM>, and brake <NUM>, which will be described later. That is, as shown in <FIG>, power supply <NUM>, motor driver <NUM>, motor <NUM>, and brake <NUM> belong to a high voltage power supply system.

Main frame <NUM> is provided with seat 101A, footrest 101B, backrest 101C, and armrest 101D. Armrest 101D is provided with joystick 101E.

A pair of training wheels <NUM> are installed on left and right sides at a front of electric trolley <NUM>. A pair of driving wheels <NUM> are installed on left and right sides at a rear of electric trolley <NUM>, and freely rotate around a rotation shaft (not shown) of motor <NUM>. Motor <NUM> is provided for each of left and right driving wheels <NUM>, and drives each of left and right driving wheels <NUM> independently. Brake <NUM> is provided for each of left and right driving wheels <NUM>, and brakes each of left and right driving wheels <NUM>. Power supply <NUM> supplies electric power to motor <NUM>.

Detector <NUM> includes at least one of obstacle detector 107A, area detector 107B, speed detector 107C, and step detector 107D which is an example of a road surface detector. Detector <NUM> is connected to driving commander <NUM> and safety controller <NUM>, which will be described later.

Obstacle detector 107A is disposed, for example, near a front of electric trolley <NUM>. Obstacle detector 107A detects an obstacle by measuring a distance to a surrounding object, and outputs detected information to safety controller <NUM>, which will be described later. Specifically, obstacle detector 107A is, for example, a laser sensor, which irradiates a periphery of electric trolley <NUM> with infrared laser light to scan a fan-shaped field centered on the sensor by approximately <NUM> degrees in a horizontal direction with a fine pitch such as every <NUM> degrees. Further, obstacle detector 107A detects the distance to the surrounding object based on time until reflected light is observed. A Time of Flight (TOF) sensor may be used as obstacle detector 107A. In this case, obstacle detector 107A is realized by a simple configuration rather than the laser sensor. In addition, a stereo camera may be used as obstacle detector 107A. In this case, obstacle detector 107A can acquire color information and the like in addition to depth information. Therefore, it is possible to acquire more detailed information about a surrounding environment and an obstacle and it is possible to realize highly accurate operation control and accurate obstacle avoidance.

Area detector 107B is disposed, for example, near the front of electric trolley <NUM>. Area detector 107B detects area information of indicating whether a current travel area is a travelable area where the electric trolley can travel safely or a dangerous area, and outputs the detected area information to safety controller <NUM>. Specifically, area detector 107B receives a signal from a signal transmitter fixed to a travel environment side, and detects an area of the current travel area.

Speed detector 107C is connected to, for example, motor <NUM> or is disposed in the vicinity of motor <NUM>. Speed detector 107C detects a travel speed of electric trolley <NUM> and outputs information of the detected speed to safety controller <NUM>. Specifically, speed detector 107C calculates rotation speeds of motor <NUM> and driving wheel <NUM> by reading a rotation angle of motor <NUM>, and detects the travel speed of electric trolley <NUM>.

Step detector 107D is disposed, for example, near the front of electric trolley <NUM>. Step detector 107D detects a step on a travel road surface and outputs information of the detected step to safety controller <NUM>. Specifically, step detector 107D is, for example, a laser sensor, which irradiates the periphery of electric trolley <NUM> with infrared laser light to scan the fan-shaped field centered on the sensor by approximately <NUM> degrees in a height direction with the fine pitch such as every <NUM> degrees. Further, step detector 107D detects a distance to the travel road surface based on the time until the reflected light is observed. Further, it is determined that a step exists on the travel road surface based on a predetermined condition such as a case where the distance to the travel road surface is not continuous or a case where the distance is significantly changed. The TOF sensor may be used as step detector 107D. In this case, step detector 107D is realized by a simpler configuration than the laser sensor. In addition, a stereo camera may be used as step detector 107D. In this case, step detector 107D can acquire color information and the like in addition to the depth information. Therefore, it is possible to acquire more detailed information about the step and it is possible to realize highly accurate operation control and accurate step avoidance.

In each of obstacle detector 107A, area detector 107B, speed detector 107C, and step detector 107D, a configuration of a sensor and the like for detecting state information may be grouped with a configuration of a processor and the like for converting the detected state information into information to be output to safety controller <NUM> or for calculating the state information.

The information detected by detector <NUM> may be further used for improving travel property of electric trolley <NUM> such as obstacle avoidance and path generation. At this time, it is desirable that, instead of safety controller <NUM>, driving commander <NUM>, which will be described later, performs control to improve the travel property based on the information detected by detector <NUM>. That is, it is desirable that a configuration in which the detected information by detector <NUM> is processed and output for improving the travel property is separately configured from a configuration in which the detected information is processed and output for improving safety. As a result, even in a case where a failure or defect occurs in any of the configurations and an abnormality occurs in the control, the operation of electric trolley <NUM> can be stopped by the other configuration. For example, in a case where an abnormality occurs in the control performed by driving commander <NUM>, safety controller <NUM> performs control to stop the driving of electric trolley <NUM> based on the information detected by detector <NUM>, as will be described later. In addition, in a case where an abnormality occurs in the control performed by safety controller <NUM>, driving commander <NUM> performs control to stop the driving of electric trolley <NUM> based on the operation amount of joystick 101E.

Control box <NUM> is provided with motor driver <NUM>, driving commander <NUM>, operation blocker <NUM>, control blocker <NUM>, and safety controller <NUM>. As described above, motor driver <NUM> belongs to the high voltage power supply system, but driving commander <NUM>, operation blocker <NUM>, control blocker <NUM>, and safety controller <NUM> belong to a low voltage power supply system. The electric power is supplied from power supply <NUM> to driving commander <NUM>, safety controller <NUM>, and the like, which belong to the low voltage power supply system via, for example, a step-down transformer.

It is preferable that control box <NUM>, power supply <NUM>, and the like are provided separately from seat 101A, backrest 101C, and the like in order to reduce discomfort to a passenger due to exhausted heat. In addition, it is preferable that control box <NUM>, power supply <NUM>, and the like are provided under electric trolley <NUM> in order to reduce instability because a center of gravity of electric trolley <NUM> becomes high.

In a case where the electric power for operation is supplied from power supply <NUM>, motor driver <NUM> controls the rotation of each motor <NUM> to operate motor <NUM>.

Motor driver <NUM> is in a state in which motor <NUM> can be controlled by inputting an operation permission signal from driving commander <NUM>. Thereafter, motor driver <NUM> controls rotation of motor <NUM> so as to operate motor <NUM> according to a control signal input from driving commander <NUM>. That is, motor driver <NUM> does not control motor <NUM> unless the operation permission signal is input from driving commander <NUM>. For example, motor driver <NUM> does not control motor <NUM> in a case where the control signal is input from driving commander <NUM> in a state in which the operation permission signal is not input from driving commander <NUM>.

In a case where driving commander <NUM> can give a command to motor driver <NUM>, driving commander <NUM> outputs the operation permission signal to motor driver <NUM>. Thereafter, in a case where the operation amount of joystick 101E is input, driving commander <NUM> determines a rotation speed of motor <NUM> based on the operation amount of joystick 101E, and outputs the control signal to motor driver <NUM>. Here, the control signal includes a control value based on the rotation speed of motor <NUM>.

Here, the case where driving commander <NUM> can give the command to motor driver <NUM> will be described. For example, in a case where driving commander <NUM> detects rise of power supply <NUM> of electric trolley <NUM>, driving commander <NUM> may transmit the operation permission signal. That is, driving commander <NUM> transmits the operation permission signal in a case where the travel control becomes possible. At this time, in a case where driving commander <NUM> detects that electric trolley <NUM> is stopped for a predetermined period for saving electric power, driving commander <NUM> may stop transmission of the operation permission signal. In addition, driving commander <NUM> may transmit the operation permission signal in a case where a failure of detector <NUM>, an abnormality of safety controller <NUM>, or the like is not generated and electric trolley <NUM> does not have a problem on travel. Here, the abnormality indicates, for example, a state in which power is not supplied to detector <NUM>, a state in which communication between communication configurations cannot be performed, and the like. Driving commander <NUM> confirms whether or not the states occur by inputting the detected information from detector <NUM> or performing communication. It is preferable that driving commander <NUM> transmits the operation permission signal in a case where the states do not occur. In addition, driving commander <NUM> may transmit the operation permission signal in a case where it is determined that there is no problem on the travel in the surrounding environment of electric trolley <NUM> based on the detected information by detector <NUM>. In addition, driving commander <NUM> may transmit the operation permission signal in a case where an instruction is input by a manual operation by a user. For example, the transmission of the operation permission signal may be performed in a case where a brake device included in electric trolley <NUM> is released by a passenger, or an instruction of the user to operate electric trolley <NUM> may be input using a terminal or the like capable of communicating with electric trolley <NUM>. In addition, the case where driving commander <NUM> can give the command to motor driver <NUM> may be automatically determined by driving commander <NUM> or may be input manually.

Driving commander <NUM> may continuously transmit the operation permission signal while determining to be capable of giving the command to motor driver <NUM>, and may stop transmission of the operation permission signal in a case of not being capable of giving the command to motor driver <NUM>.

In this way, operation commander <NUM> transmits the operation permission signal in addition to the control signal. As a result, even in a case where operation commander <NUM> erroneously transmits the control signal, the erroneously transmitted control signal can be invalidated by not transmitting the operation permission signal. Therefore, safety can be improved.

Not only the operation amount of joystick 101E but also information related to, for example, a preset speed may be further used for determination of the rotation speed of motor <NUM> by driving commander <NUM>. In a case where the maximum speed is preset, driving commander <NUM> determines the rotation speed of motor <NUM> so that electric trolley <NUM> operates at a speed which is equal to or less than the set maximum speed. Driving commander <NUM> may output the operation permission signal or the control signal at the same time to each of motor drivers <NUM>, or may perform individual input. In addition, joystick 101E may have another form such as a handle or a remote controller.

In a case where an operation blocking signal is input from safety controller <NUM>, operation blocker <NUM> blocks the operation permission signal input from driving commander <NUM> to motor driver <NUM>. In a case where the operation blocking signal is not input from safety controller <NUM>, operation blocker <NUM> does not block the operation permission signal output from driving commander <NUM> to motor driver <NUM>.

Operation blocker <NUM> is a switching element, and is configured with, for example, a tri-state buffer. A configuration is used in which operation blocker <NUM> is provided for each motor driver <NUM> one by one, but the present disclosure is not limited thereto, and the operation permission signal input from driving commander <NUM> to each motor driver <NUM> may be blocked by one operation blocker <NUM>. However, in a case where operation blocker <NUM> is provided for each motor driver <NUM> one by one, it is possible to cause operation blocker <NUM> to easily correspond to specification of each motor driver <NUM> in a case where motor driver <NUM> is replaced according to driving wheel <NUM> or motor <NUM>, in a case where the number of motor drivers <NUM> is increased or decreased, and the like.

In the case where the control blocking signal is input from safety controller <NUM>, control blocker <NUM> blocks the control signal input from driving commander <NUM> to motor driver <NUM>. In the case where the control blocking signal is not input from safety controller <NUM>, control blocker <NUM> does not block the control signal output from driving commander <NUM> to motor driver <NUM>.

Control blocker <NUM> is a switching element, and is configured with, for example, a tri-state buffer. A configuration is used in which control blocker <NUM> is provided for each motor driver <NUM> one by one, but the present disclosure is not limited thereto, and the operation permission signal input from driving commander <NUM> to each motor driver <NUM> may be blocked by one control blocker <NUM>. However, in a case where control blocker <NUM> is provided for each motor driver <NUM> one by one, it is possible to cause control blocker <NUM> to easily correspond to the specification of each motor driver <NUM> in the case where motor driver <NUM> is replaced according to driving wheel <NUM> or motor <NUM>, in the case where the number of motor drivers <NUM> is increased or decreased, and the like.

Safety controller <NUM> determines whether or not it is necessary to stop the driving of electric trolley <NUM> based on the information input from detector <NUM>. In a case where safety controller <NUM> determines that it is necessary to stop the driving of electric trolley <NUM>, safety controller <NUM> outputs the operation blocking signal to operation blocker <NUM> and the control blocking signal to control blocker <NUM>, respectively, through paths independent of each other, and stops driving of motor <NUM>. That is, safety controller <NUM> includes at least one of a connector for inputting the operation blocking signal to operation blocker <NUM> and a connector for inputting the control blocking signal to control blocker <NUM>.

Safety controller <NUM> stops an operation of motor driver <NUM> by controlling the output of the operation permission signal and an operation of motor <NUM> independently of each other. In the present exemplary embodiment, safety controller <NUM> stops the control of motor <NUM> by motor driver <NUM> by controlling operation blocker <NUM> and control blocker <NUM> independently of each other. As a result, two circuits exist for inputting signals for stopping the driving of motor <NUM>, so that the driving of motor <NUM> can be stopped more reliably. In addition, safety controller <NUM> may brake driving wheel <NUM> by operating brake <NUM> by inputting a brake signal to brake <NUM> in a case where the speed is not sufficiently reduced at the same time or after a certain time elapses. The case where the speed is not sufficiently decelerated indicates, for example, a case where the speed is not zero. As a result, three circuits exist for inputting signals for stopping the driving of motor <NUM>, so that the driving of motor <NUM> can be stopped more reliably.

Here, safety controller <NUM> determines whether or not it is necessary to stop the driving of electric trolley <NUM>, for example, as follows.

In a case where safety controller <NUM> detects that a speed of electric trolley <NUM>, which is detected by speed detector 107C, exceeds, for example, a preset speed, safety controller <NUM> determines that it is necessary to stop the driving of electric trolley <NUM>. At this time, specifically, a situation is conceivable in which motor driver <NUM> is not normally controlled due to an abnormality or the like in driving commander <NUM>, so that there is a problem in that rough driving or collision occurs.

Alternatively, safety controller <NUM> determines that it is necessary to stop the driving of electric trolley <NUM> in a case where obstacle detector 107A detects an obstacle in a very vicinity. At this time, specifically, there is a problem in that a collision with the obstacle in the vicinity may occur. Alternatively, more simply, in a case where obstacle detector 107A detects an obstacle in a predetermined area, safety controller <NUM> may determine that it is necessary to stop the driving of electric trolley <NUM>. At this time, the driving of electric trolley <NUM> is stopped at a time in which the obstacle separated from electric trolley <NUM> by a certain distance is detected, so that the collision can be prevented.

Alternatively, safety controller <NUM> determines that it is necessary to stop the driving of electric trolley <NUM> based on the speed of electric trolley <NUM> detected by speed detector 107C and the distance to the surrounding obstacle detected by obstacle detector 107A. More specifically, safety controller <NUM> estimates a travel trace in a case where electric trolley <NUM> is braked based on a current travel speed of electric trolley <NUM> detected by speed detector 107C, and determines that it is necessary to stop the driving of electric trolley <NUM> in a case where the obstacle is detected by obstacle detector 107A inside the travel trace. At this time, the obstacle exists in the estimated travel path of electric trolley <NUM>, so that there is a problem in that a collision occurs.

Alternatively, safety controller <NUM> determines that it is necessary to stop the driving of electric trolley <NUM> in a case where step detector 107D detects a concave step on the travel road surface. At this time, specifically, it is conceivable that electric trolley <NUM> is overturned or falls due to the concave step, so that there is a problem in that overturn of the passenger or harm of a surrounding person below the concave step occurs.

Alternatively, safety controller <NUM> determines that it is necessary to stop the driving of electric trolley <NUM> based on the area information detected by area detector 107B. Specifically, safety controller <NUM> determines whether or not it is necessary to stop the driving of electric trolley <NUM> based on whether or not the current travel area is the dangerous area. For example, safety controller <NUM> may determine the travelable area while the transmitter is installed in the travelable area and safety controller <NUM> receives the signal, and safety controller <NUM> may determine the dangerous area in a case where the signal is blocked. In addition, in a case where the transmitter is installed in the dangerous area and safety controller <NUM> receives a signal, safety controller <NUM> may determine the dangerous area. In addition, an ID and attribute information may be added to the signal of the signal transmitter installed on the travel environment, and safety controller <NUM> may determine whether the travel area is the travelable area or the dangerous area based on the added content.

Although driving commander <NUM> and safety controller <NUM> may be configured on the same microcomputer, it is desirable that driving commander <NUM> and safety controller <NUM> are separately configured by separating cores in the microcomputer. More desirably, driving commander <NUM> and safety controller <NUM> may be physically configured separately by being configured by separate microcomputers or the like. As a result, even in a case where a failure or defect occurs in any of driving commander <NUM> and safety controller <NUM> and an abnormality occurs in the control, the operation of electric trolley <NUM> can be stopped by the other. For example, in a case where an abnormality occurs in the control performed by driving commander <NUM>, safety controller <NUM> performs control to stop the driving of electric trolley <NUM> based on the information detected by detector <NUM>. In addition, in a case where an abnormality occurs in the control performed by safety controller <NUM>, for example, a fact of the occurrence of the abnormality is notified to the user by using a display device, a notification device, or the like. As a result, a side of the user can recognize that safety controller <NUM> cannot be operated, thereby contributing to performing control to stop the driving of electric trolley <NUM> by driving commander <NUM> based on the operation amount of joystick 101E by the user. In addition, for example, in a case where an abnormality occurs in the control performed by safety controller <NUM>, safety controller <NUM> may be designed so that safety controller <NUM> automatically outputs the operation blocking signal and the control blocking signal. By doing so, the driving of electric trolley <NUM> can be stopped at a time in which an abnormality occurs in safety controller <NUM>, and travel can be performed with higher safety.

In a case where safety controller <NUM> is configured, detector <NUM> is disposed on electric trolley <NUM> to be connected to safety controller <NUM> by wire or wirelessly. Alternatively, detector <NUM>, which is already mounted on electric trolley <NUM>, and safety controller <NUM> are connected by wire or wirelessly. Next, operation blocker <NUM> is disposed between the connectors for inputting the operation permission signal from driving commander <NUM> to motor driver <NUM>, and operation blocker <NUM> and safety controller <NUM> are connected in wired or wirelessly. In addition, control blocker <NUM> is disposed between connectors for inputting the control signal from driving commander <NUM> to motor driver <NUM>, and control blocker <NUM> and safety controller <NUM> are connected in wired or wirelessly. However, it is desirable that operation blocker <NUM>, control blocker <NUM>, and safety controller <NUM> react at a response speed as fast as possible, and a wired connection is preferable.

Driving commander <NUM> and safety controller <NUM> may be realized by a computer program. A computer that realizes the above-described driving commander <NUM> and safety controller <NUM> using the program may illustratively include a processor, an output device, a memory, a storage, and a power supply circuit. The components are connected to a bus and can communicate with each other.

The processor is an example of a circuit or device having arithmetic capacity. As the processor, for example, at least one of a Central Processing Unit (CPU), a Micro Processing Unit (MPU), and a Graphics Processing Unit (GPU) may be used.

The output device may include, for example, a display (or monitor).

The memory stores, for example, a program executed by the processor and data or information processed according to the execution of the program. The memory may include a Random Access Memory (RAM) and a Read Only Memory (ROM). The RAM may be used as a work memory of the processor. The "program" may be referred to as "software" or "application".

The storage stores the program executed by the processor and data or information processed according to the execution of the program. The storage may include, for example, a semiconductor drive device such as a Hard Disk Drive (HDD) or a Solid State Drive (SSD). In addition to or in place of the semiconductor drive device, a non-volatile memory, such as a flash memory, may be included in the storage.

The program and/or data may be provided in the form of being recorded on a computer (processor) readable recording medium. A flexible disc, a CD-ROM, a CD-R, a CD-RW, an MO, a DVD, a Blu-ray disc, a portable hard disk, and the like may be provided as examples of the recording media. In addition, semiconductor memories, such as a Universal Serial Bus (USB) and a memory, are also examples of recording media.

In addition, the program and/or data may be provided (downloaded), for example, from a server to the computer via a communication line. For example, the program and/or the data may be provided to the computer via a communication device and may be stored in the memory and/or the storage. The program and/or data may also be provided to the computer via an input device and may be stored in the memory and/or the storage.

In the present exemplary embodiment, an example is shown in which operation blocker <NUM> blocks the operation permission signal output from driving commander <NUM> to motor driver <NUM>, but the present disclosure is not limited thereto. For example, the operation permission signal may be generated by dividing a voltage from power supply <NUM>. Even in this case, operation blocker <NUM> is configured to block the operation permission signal. In addition, the operation of motor driver <NUM> may be stopped by outputting an operation non-permission signal, which is used to prevent the operation permission signal from being output, from safety controller <NUM> to driving commander <NUM> without providing operation blocker <NUM>. In addition, the operation of motor driver <NUM> may be stopped by outputting the control signal, which is used to reduce the amount of electric power to be supplied to motor <NUM> to <NUM>, from safety controller <NUM> to driving commander <NUM> without providing control blocker <NUM>.

Safety controller <NUM> may release the blocking after confirming that the stop of electric trolley <NUM> elapses for a certain time based on the travel speed of electric trolley <NUM> detected by speed detector 107C. Specifically, in a case where safety controller <NUM> confirms that the stop of electric trolley <NUM> elapses for the certain time, safety controller <NUM> stops the output of the control blocking signal and the operation blocking signal. Alternatively, safety controller <NUM> may confirm that there is no problem on the travel in the surrounding environment of electric trolley <NUM> based on the detected information by detector <NUM>, and may release the blocking. Specifically, safety controller <NUM> stops the output of the control blocking signal and the operation blocking signal based on any of a case where the obstacle is not detected by obstacle detector 107A, a case where the current travel area detected by area detector 107B is not the dangerous area, and a case where the step is not detected by step detector 107D. Alternatively, safety controller <NUM> may release the blocking by a manual operation by the user. Specifically, in a case where an instruction to release the blocking is input using the input device (which may be, for example, a device, such as a switch, that inputs only an intention or may be a device that includes a display unit, such as a touch panel, so as to present other information) by a passenger, a companion, or the like, safety controller <NUM> stops the output of the control blocking signal and the operation blocking signal.

A configuration included in electric trolley <NUM> does not need to be limited to the disposition, a shape, and a size shown in <FIG>, and can be appropriately changed according to a design of electric trolley <NUM>.

As described above, instead of the interruption circuit that interrupts the power supply circuit, electric trolley <NUM> according to the present disclosure includes operation blocker <NUM> that blocks the operation permission signal transmitted from operation commander <NUM>, and control blocker <NUM> that blocks the control signal. Since the power supply circuit belongs to the high voltage power supply system, the interruption circuit is large and heavy. On the other hand, operation blocker <NUM> and control blocker <NUM>, which are disposed between driving commander <NUM> and motor driver <NUM>, belong to the low voltage power supply system. Therefore, electric trolley <NUM> according to the present disclosure can mount a configuration capable of stopping travel more reliably with a small size and a light weight.

Electric trolley 100a according to a second exemplary embodiment of the present disclosure will be described with reference to <FIG> is a schematic diagram of stop control according to the second exemplary embodiment of the present disclosure.

Here, in electric trolley 100a according to the second exemplary embodiment, differences from electric trolley <NUM> according to the first exemplary embodiment will be mainly described. Specifically, in electric trolley 100a according to the second exemplary embodiment, a connection relationship between the detector, the safety controller, and the driving commander is different.

As shown in <FIG>, detector <NUM> is connected only to safety controller 113a. Driving commander 110a acquires information output by detector <NUM> via safety controller 113a.

Specifically, safety controller 113a includes manager <NUM>. Manager <NUM> manages detector <NUM>, acquires the information output by detector <NUM>, and outputs the acquired information to driving commander 110a.

That is, safety controller 113a acquires the information output from detector <NUM> prior to driving commander 110a, and confirms content thereof. Therefore, safety controller 113a can confirm information to be input to driving commander 110a. Further, safety controller 113a can guarantee that driving commander 110a and safety controller 113a are operated according to information of the same detector <NUM>. Since detector <NUM> has a single output destination, detector <NUM> can be applied even to a detector in which it is difficult to branch an output signal.

Safety controller 113a may output the information from detector <NUM> to driving commander 110a only in a case where it is determined to be a safety state based on the information from detector <NUM>. In this case, safety controller 113a can operate driving commander 110a based on the information of detector <NUM> which determines the safe state.

In electric trolley <NUM> according to the first exemplary embodiment, feedback to detector <NUM> is provided from two systems including driving commander <NUM> and safety controller <NUM>. On the other hand, in the present exemplary embodiment, manager <NUM> can centrally manage the feedback to detector <NUM>.

Electric trolley 100b according to a third exemplary embodiment of the present disclosure will be described with reference to <FIG> is a schematic diagram of stop control according to the third exemplary embodiment of the present disclosure.

Here, in electric trolley 100b according to the third exemplary embodiment, differences from electric trolley <NUM> according to the first exemplary embodiment will be mainly described. Specifically, electric trolley 100b according to the third exemplary embodiment has a function of monitoring operations of operation blocker <NUM> and control blocker <NUM>.

As shown in <FIG>, safety controller 113b according to the present exemplary embodiment includes first monitor <NUM> and second monitor <NUM>. First monitor <NUM> monitors a signal output from operation blocker <NUM> to motor driver <NUM>. Second monitor <NUM> monitors a signal output from control blocker <NUM> to motor driver <NUM>.

As a result, in a case where the operation blocking signal and the control blocking signal are output, safety controller 113b can confirm whether or not operation blocker <NUM> and control blocker <NUM> normally function.

Safety controller 113b may include a single monitor that integrates the functions of the two monitors. In addition, safety controller 113a according to the second exemplary embodiment may include first monitor <NUM> and second monitor <NUM>.

Electric trolley 100c according to a fourth exemplary embodiment of the present disclosure will be described with reference to <FIG> is a schematic diagram of stop control according to the fourth exemplary embodiment of the present disclosure.

Here, in electric trolley 100c according to the fourth exemplary embodiment, differences from electric trolley <NUM> according to the first exemplary embodiment will be mainly described. Specifically, in electric trolley 100c according to the fourth exemplary embodiment, a configuration in which the operation blocking signal is output is independent of a configuration in which the control blocking signal is output.

As shown in <FIG>, safety controller 113c according to the present exemplary embodiment includes first determiner <NUM> and second determiner <NUM>. In a case where first determiner <NUM> determines that it is necessary to stop driving of electric trolley 100c based on information from detector <NUM>, first determiner <NUM> outputs the operation blocking signal to operation blocker <NUM>. In a case where second monitor <NUM> determines that it is necessary to stop the driving of electric trolley 100c based on the information from detector <NUM>, second monitor <NUM> outputs the control blocking signal to control blocker <NUM>.

It is desirable that first determiner <NUM> and second determiner <NUM> are separately configured by separating cores in the same microcomputer. More desirably, first determiner <NUM> and second determiner <NUM> may be physically configured separately by being configured by separate microcomputers or the like.

First determiner <NUM> and second determiner <NUM> perform mutual monitoring and monitor that other determiners normally operate. As a result, even in a case where first determiner <NUM> or second determiner <NUM> fails, the blocking signal by the other determiner is reliably output.

Claim 1:
An electric trolley (<NUM>) that travels by controlling a motor (<NUM>) fitted to a driving wheel (<NUM>) of the electric trolley (<NUM>) using a motor driver (<NUM>) of the electric trolley (<NUM>), the electric trolley (<NUM>) comprising:
a safety controller (<NUM>) that determines whether or not to stop driving of the driving wheel (<NUM>); and
a driving commander (<NUM>) that outputs, to the motor driver (<NUM>), (i) an operation permission signal for permitting the motor (<NUM>) to be operated and (ii) a control signal for controlling an operation of the motor (<NUM>),
an operation blocker (<NUM>) that is provided between the driving commander (<NUM>) and the motor driver (<NUM>), and blocks the operation permission signal based on an operation blocking signal input from the safety controller (<NUM>); and
a control blocker (<NUM>) that is provided between the driving commander (<NUM>) and the motor driver (<NUM>), and blocks the control signal based on a control blocking signal input from the safety controller (<NUM>), wherein
when the safety controller (<NUM>) determines to stop the driving of the driving wheel (<NUM>), the safety controller (<NUM>) outputs the operation blocking signal to the operation blocker (<NUM>) and outputs the control blocking signal to the control blocker (<NUM>), and performs control to stop inputs of the operation permission signal and the control signal to the motor driver (<NUM>).